How do I book a party?

Right here — pick your location, package and time. Your party coordinator calls the week of the party — the Sunday before, or by Wednesday at the latest, when you'll actually have your numbers — to confirm the details and any add-ons. Extras are paid the Thursday before your event.

How do I book a party?

Right here — pick your location, package and time. Our event coordinator reaches out at least two weeks before the party to confirm the details and any add-ons, so you know exactly what to expect, and you'll have the chance for a 30-minute planning call. Extras are paid the Thursday before your event.

How far ahead can I book?

Up to four months ahead, at both locations — the calendar shows every open slot in that window. Weekend slots go first, so book early if your date matters.

How soon can I arrive?

You may arrive 20 minutes before your scheduled party. Our staff may still be cleaning up from the previous party or event.

How soon can I arrive?

You may arrive 15 minutes before your scheduled party. Our staff may still be cleaning up from the previous party or event.

How soon can my guests arrive?

To keep everything on schedule, we kindly ask that guests arrive at the party start time.

Would it be possible to book a party for a time or date not listed on the website?

Yes — email us and we'll do our best to accommodate you.

Yes — every package includes a set number of adults (it's on each package card; Premier includes 16 adults with 16 kids). Each extra kid includes 1 more adult at no extra charge, up to the package maximum (22 kids and 22 adults for Premier). If more adults come than children, the extra adults are $25 each.

When do I need to give my final head count?

Final numbers are due by the Thursday before your party. That's when we set the room, order the food and pack the projects — Friday is too late for us to have everything ready. After the deadline, added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge.

When do I need to give my final head count?

Final numbers are due by the Thursday before your party. That's when we set the room, order the food and pack the projects. After the deadline, added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge.

Can an Elite Drop-Off party have more than 18 kids?

The Small Party Room holds up to 18 kids, so 18 is the Elite maximum. If your list might be bigger, an upgrade to a Premier party in the large party room is possible only when that room is still available — and it often isn't. If you're unsure of your count, we recommend booking a Premier party from the start.

Can I add kids or adults after the final head count?

Usually, yes: add kids in your party planner. After the deadline, added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge. Guests who arrive on the day without notice are charged at the end of the party at the extra-guest rate plus a $10 late-addition premium: $50 per additional kid and $35 per additional adult on Premier (other packages follow the same rule on their own rates).

Can I add kids or adults after the final head count?

Usually, yes. Kids added in your party planner are $40 each on Premier, VIP Glow and Premier Plus. After the head-count deadline (the Thursday before your party), added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge. Kids added on the day of the party are $50 + tax each, charged at the end of the party. Extra adults are $25 each, whether added in advance or on the day.

What happens if fewer guests arrive than I paid for?

We staff and prepare for the guest count you confirm, so if fewer kids or adults come than you paid for, there are no refunds or credits.

What happens if more guests arrive than I paid for?

If more kids or adults come than expected, the additional guest price is paid at the end of the party — extra kids at the same-day rate ($50 + tax each on Premier, VIP Glow and Premier Plus) and extra adults at $25 each.

Can I count children as part of the adult guest number?

No — children and adults can't be swapped. If there are more children or adults than your party's initial number, the respective additional guest price is paid at the end of the party.

What if my guests stay past the end time?

We're happy when guests love the space! Families are welcome to buy tickets to stay and play. If they don't, the additional time fee is charged automatically — you have a 15-minute grace period to pack up.

Am I allowed to hire outside vendors or caterers?

We provide comprehensive in-house services and catering to keep the event smooth. Outside vendors or caterers are welcome with advance approval and a service fee — and we keep it simple: give us the vendor's business name and email address and we handle the paperwork. They complete everything, including the certificate of insurance, in a few clicks.

What are the table sizes and room setup like?

Tables are 32 in. × 32 in. and 29.5 in. tall. Typically 9 tables are used for the take-home activity and eating, with 2 more as the cake/dessert table. Elite parties include up to 8 tables plus 1 cake table. Specific layout requests are welcome in advance.

What are the table sizes and room setup like?

Bringing tablecloths? Email us and we'll send you the exact table measurements and the number of tables set for your party size. Specific layout requests are welcome in advance.

Can I hang decorations?

Yes — with the painter's tape we provide, which comes off our walls cleanly. Please don't use glue dots, regular tape or glue. Weighted balloons are welcome; confetti and sparklers aren't.

Can I have cake or balloons delivered for the party?

Deliveries must be on the day of the event, during business hours, and we must be notified in advance. We don't have fridge or freezer space for cakes, and we can't be responsible for delivery mishaps. Talk to our event coordinator if you'd like to drop decorations off early.

Can I have cake or balloons delivered for the party?

Deliveries must be on the day of the event, during business hours, and we must be notified in advance. We can't be responsible for delivery mishaps. Talk to our party coordinator if you'd like to drop decorations off early.

Can my cake be refrigerated?

Usually, yes — our party staff can refrigerate a cake if we know ahead of time, so please mention it when you plan the party so we can make the space. Ice-cream cakes aren't a good fit.

Do you offer kosher pizza?

Yes — kosher pizza can be ordered through us for the party at an additional cost; ask your coordinator and it's added to your order. More generally, families who need to bring in food for religious reasons are welcome to — just let us know in advance so we can plan the table.

What if the birthday child gets sick?

In extenuating circumstances such as sickness or injury we'll do our best to reschedule at a mutually convenient date. As per our cancellation policy, we're not able to offer refunds for party cancellations.

What if I leave personal party items behind?

It happens! Please pick up your items within 48 hours at the location; after that they're donated per our lost & found policy.

Can adults have a drink at the party?

In NYC, yes — we hold a beer and wine license. Choose a mimosa or bellini bar, a beer and wine package, or an à la carte bar in your party dashboard after booking.

What is your tipping policy?

Gratuity isn't included in your party price, and tipping is never required. If your party team made the day special, tips are always appreciated. They're shared among the hosts who ran your party, and cash or card is welcome.

Kids' Birthday Parties in NJ & NYC — Genius Gems

The birthday party you get to enjoy too.

A private party room, experienced party leaders, one take-home project for every kid, magnetic-tile building and games, and pizza and juice for the kids. You bring the cake — we handle everything else.

Book your party

Ages: 5+ · 4-year-olds with a full rent-out
Party length: 1.5 hours minimum
Included: Pizza, juice & a take-home project
Run by: Dedicated party leaders

Choose your package

Every package includes a dedicated party room, the leaders, one take-home project for every kid, and pizza and juice for the kids. Each card shows exactly how many kids and adults are included — and how big the party can grow for an additional cost.

Millburn, NJ

Premier · Millburn — Your own private party room with 3 dedicated leaders to run the fun.
$599 + tax · 1 hr 30 min party · Includes 16 kids and 16 adults · For an additional cost, up to 22 kids and 22 adults. · Extra kids $40 each · Each extra kid includes 1 more adult. Adults beyond your kid count are $25 each. · Ages 5+ · Private Party Room

Book Premier · Millburn
Premier Plus · Millburn — The full Genius Gems experience — indoors & outdoors, all yours. Drop-off friendly.
$1499 + tax · 1 hr 30 min party · Includes 25 kids and 25 adults · For an additional cost, up to 35 kids and 35 adults. · Extra kids $40 each · Each extra kid includes 1 more adult. Adults beyond your kid count are $25 each. · Ages 4+ · Full Facility

Book Premier Plus · Millburn
VIP Glow Party · Millburn — Saturday evening magic with disco lights and an unforgettable glow atmosphere.
$999 + tax · 1 hr 30 min party · Includes 25 kids and 25 adults · For an additional cost, up to 35 kids and 35 adults. · Extra kids $40 each · Each extra kid includes 1 more adult. Adults beyond your kid count are $25 each. · Ages 5+ · Full Facility

Book VIP Glow Party · Millburn

New York City

Elite Drop-Off · NYC — Drop-off party for ages 7 and up.
$799 + tax · 1 hr 30 min party · Includes 12 kids and 4 adults (it's a drop-off) · For an additional cost, up to 18 kids and 12 adults. · Extra kids $100 each · Extra adults who stay are $29.99 each. · Ages 7+ · Drop-off · Small Party Room

Book Elite Drop-Off · NYC
Premier Party · NYC — Our signature party — the perfect mix of creativity, play, and celebration.
$1499 + tax · 1 hr 30 min party · Includes 20 kids and 25 adults · For an additional cost, up to 30 kids and 30 adults. · Extra kids $50 each · Each extra kid includes 1 more adult. Adults beyond your kid count are $29.99 each. · Ages 5+ · Large Party Room

Book Premier Party · NYC
VIP Glow Party · NYC — An evening spectacle with disco lights, music, and the whole space glowing.
$3000 + tax · 1 hr 30 min party · Includes 30 kids and 45 adults · For an additional cost, up to 40 kids and 60 adults. · Extra kids $50 each · Each extra kid includes 1 more adult. Adults beyond your kid count are $29.99 each. · Ages 5+ · Full Facility

Book VIP Glow Party · NYC
Premier Plus · NYC — Take over our entire 10,000 sq ft facility for the ultimate birthday bash.
Contact us for pricing · 1 hr 45 min party · Includes 30 kids and 45 adults · For an additional cost, up to 45 kids and 75 adults. · Each extra kid includes 1 more adult. Adults beyond your kid count are $29.99 each. · Ages 5+ · Full Facility

Book Premier Plus · NYC

Every package includes

One take-home project — You pick one project for all the kids — glitter tiles or slime — and every kid makes one to keep. The party favor that actually gets used.
Magnetic-tile building challenges — Our party leaders run building magnetic-tile challenges — castles, towers and other crowd-favorites.
Magnetic-tile building challenges — Our leaders bring the building to you — castles, towers and other crowd-favorites, right in your party room.
Dedicated party leaders — From start to finish, our team runs the room. Parents can to be guests.
Adults included — Every package includes a set number of adults — it's on each package card, along with how many more can join for an additional cost.
Fresh pizza and juice for the kids — Served at the table when it's time to eat. Vegan and gluten-free pizza can be added for an extra cost, and kosher pizza can be ordered for the party.
Fresh pizza and juice for the kids — Served at the table when it's time to eat. Vegan and gluten-free pizza can be added for an extra cost.
Your own party room — A dedicated space for the whole party -- white plastic tablecloths, forks and off-white compostable plates incluced. Decor is not included; families choose one of our decor packages or bring their own.
Your own party room, start to finish — Premier parties happen entirely in your private party room — the building, the project, the food and the cake. Tables set, tablecloths and servingware included.
The cake moment — Bring the cake or cupcakes; we'll provide the lighter and knife.
Café access for adults — Grown-ups can grab coffee and snacks in the café while the party runs — and in NYC we're licensed for beer and wine if they're staying.
Setup and cleanup — You walk in to a ready room and walk out without lifting a finger.

Three party guests in wristbands holding up the glitter tiles they designed

How the party goes

Parties run 1.5 hours minimum — longer with extra time or a full rent-out. Here's the shape of it.

Arrive to a room that's ready — When guests walk in, your private party room is already set up and our experienced staff take it from there.
Build and play — in your room — In Millburn we bring the fun to you: our staff lead magnetic-tile building and games right in your private party room (full-venue parties get the whole floor). Big builds, big cheers, everyone involved.
Make the take-home project — Then the tables turn into a workshop for the one project you chose — glitter tiles or slime — with a party leader guiding every step.
Make the take-home project — In NYC the project comes first: the one project you chose — glitter tiles or slime — at the table with a party leader guiding every step. (Premier Plus parties can flip the order if you'd like.)
Build and play in the Glow Room — Next, our staff walk the kids into our Glow Room for magnetic-tile building and games — big builds, big cheers, everyone involved.
Food and cake — The kids wash their hands while staff reset the room, then it's pizza and your cake or cupcakes — though we're happy to accommodate whatever you have in mind. Then the song. Bringing goody bags? We'll hand them out — or order ours as an add-on.
Back to your party room for food and cake — While the kids are in the Glow Room, staff reset your private room — then everyone washes up at the room's own sink and settles in for food: typically pizza and your cake or cupcakes, though we're happy to accommodate whatever you have in mind. Then the song. Bringing goody bags? We'll hand them out — or order ours as an add-on.

The take-home project

Every package includes one project for the whole party — choose glitter tiles or slime, and every kid makes one. Engineering builds and themed projects are add-ons that take its place.

Glitter Tile (Pick one — included) — Kids choose charms, gems, letters and glitter to design a tile that works with magnetic-tile sets at home. Ages 5–12.
Slime (Pick one — included) — Clear base, colorant, glitter and add-ins — every kid mixes their own slime to take home. Glow-in-the-dark and color-changing powders are an upgrade. Ages 5–12.
Squishies (Upgrade — replaces the included project: $89 for up to 16 kids, then $10 each) — Upgrade the slime: every kid seals their slime into a silicone pouch to make a squishy — all the fun of slime, none of the mess. Added on top of the slime project.
LED & engineering builds (Upgrade — replaces the included project: $99 for up to 20 kids, then $5 each) — LED wands, light-up creatures and motorized fans for the older crowd — real circuits, wired by the kids. Chosen in place of the glitter tile or slime. Ages 8+.
LED & engineering builds (Upgrade — replaces the included project: $99 for up to 20 kids, then $5 each) — LED wands, light-up creatures and motorized fans for the older crowd — real circuits, wired by the kids. Chosen in place of the glitter tile or slime. Ages 7+.
Brushbot (Upgrade — replaces the included project: $89 for up to 16 kids, then $10 each) — The engineering build for younger crowds: a giant brush, a motor and a lot of giggles — every kid wires up a bot that scoots across the table. Chosen in place of the glitter tile or slime. Ages 6+.
Mad Scientist — Lab coats, goggles and a hands-on volcano experiment — this IS the project, chosen in place of the glitter tile or slime. Ages 6+.

Make it yours

Themes, food, wow-factor extras and favors — all added after booking in your party dashboard, with prices shown as you go.

Themed parties (from $199) — Pokémon, Minecraft, Robot, Rainbow, Mad Scientist, K-Pop Demon Hunters and more — themed décor, supplies and a matching project. Balloons aren't included in a theme; they're a separate add-on.
- Pokémon® Add-On — $299 for up to 20 kids, then $5 each: Celebrate with a Pokémon™-themed party featuring themed plates, decorations, trivia games, and your choice of an LED Poké Ball or Pokémon™ Glitter Tile project! This add-on includes up to 20 children. Each additional child is $5 + tax, on top of the standard $50 + tax additional guest fee. Other add-ons and guest fees are charged separately. Please note: Pokémon™ activities may reduce or replace magnetic tile building time, especially for larger parties.
- Mad Scientist Add-On — $199 for up to 20 kids, then $10 each: Turn your child's party into a science-themed adventure! Includes use of lab coats and goggles for up to 20 kids, plus a hands-on volcano experiment, in lieu of slime or a Glitter tile project, they'll build (and erupt!) themselves. Additional cost for kids after the initial 20. Recommended for ages 6+. The lab coats and goggles are for use at Genius Gems only (not to take home).
- Rainbow Add-On — $199: Celebrate with a colorful Rainbow-themed party featuring rainbow plates, decorations, fun games, and a special rainbow-inspired project! This add-on includes up to 20 children. Each additional child is $5 + tax, on top of the standard $50 + tax additional guest fee. Other add-ons and guest fees are charged separately.
- Robot Add-On — $199: Celebrate with a Robot-themed party featuring themed plates, decorations, fun robot challenges, and a special robot-inspired project! This add-on includes up to 20 children. Each additional child is $5 + tax, on top of the standard $50 + tax additional guest fee. Other add-ons and guest fees are charged separately.
- Minecraft® Add-On — $199: Level up your celebration with a Minecraft-themed party featuring themed plates, decorations, fun Minecraft-inspired challenges, and a special hands-on project! This add-on includes up to 20 children. Each additional child is $5 + tax, on top of the standard $50 + tax additional guest fee. Other add-ons and guest fees are charged separately.
- K-Pop Demon Hunters® Add-On — $350: Unleash your inner star and hero with our newest themed party experience: K-Pop Demon Hunters™! This high-energy add-on blends the glitz of K-Pop with the thrill of supernatural adventure — complete with glowing decor, music, STEM-inspired crafts, and live-action fun. This party includes a fun LED light staff (Saja Boys or HuntrX) in lieu of a glitter tile/slime. This pricing is on top of the base package, and the cost of any additional kids over 20 kids and adults over 20. (1.5 hour party) Genius Gems is not sponsored or endorsed by Sony Pictures.
Themed parties (from $199) — Pokémon, Minecraft, Robot, Rainbow and more — themed décor, supplies and a matching project. Balloons aren't included in a theme; they're a separate add-on.
- Pokémon® Add-On — $199 for up to 16 kids, then $10 each: Enjoy a Pokémon™ themed party with specially themed plates, decorations, and trivia games! Pokémon™ Parties have the choice of a special project, either an LED Pokeball or a Pokémon™ Themed Glitter Tile! Please note that in order to accommodate these extra activities, building time may be reduced, or for larger parties, this may take the place of building time. This add-on includes up to 16 kids, with an additional $10+ tax for every child beyond the initial 16.
- Unicorn Add-On — $299 for up to 16 kids, then $10 each: Make your party Unicorn themed with specially themed party supplies (big plates, table cloths, cake plates, cups, napkins, cutlery, etc.), and decorations (banners, center pieces, wall streamers, etc.)! For ages 5-7 we offer a unicorn themed glitter tile where guests are guided in choosing and arranging gems, letters, rainbow glitter, and unicorn themed charms to decorate their own Glitter Tile, which can be used on any brand of magnetic tile. For ages 8 and over we offer a LED Rainbow where guests are guided in creating an LED circuit using an LED light and a battery pack, inserting it into the rainbow laser-cut shape they decorate. This add-on includes up to 16 kids, with an additional $10+ tax for every child beyond the initial 16.
- Robot Add-On — $299 for up to 16 kids, then $10 each: Make your party Robot themed with specially themed party supplies (big plates, table cloths, cake plates, cups, napkins, cutlery, etc.), and decorations (banners, center pieces, wall streamers, etc.)! This party includes three options for a project varying on age. For ages 5-7 we offer a robot themed glitter tile where guests are guided in choosing and arranging gems, letters, glitter, and robot themed charms to decorate their own Glitter Tile, which can be used on any brand of magnetic tile. For ages 8 and over we offer a LED Robot where guests are guided in creating an LED circuit using an LED light and a battery pack, inserting it into the robot laser-cut shape they decorate. For ages 8 and over we also offer a motorized wheel where guests are guided in creating a motor, wheels, and LED wires, and a battery pack. There is an additional cost for this option. This add-on includes up to 16 kids, with an additional $10+ tax for every child beyond the initial 16.
- Minecraft® Add-On — $299 for up to 16 kids, then $10 each: Make your party Minecraft themed with specially themed party supplies (big plates, table cloths, cake plates, cups, napkins, cutlery, etc.), and decorations (banners, center pieces, wall streamers, etc.)! Recommended for ages 5-12 we offer a slime where guests are guided in using our clear base slime, glitter, colorant, and other add-ins to create their choice of a specific Minecraft theme. Recommended for ages 8-12 we offer a LED Minecraft Creeper where guests are guided in creating an LED circuit using an LED light and a battery pack, inserting it into the Minecraft creeper laser-cut shape they decorate. This add-on includes up to 16 kids, with an additional $10+ tax for every child beyond the initial 16. Genius Gems is not sponsored or endorsed by Mojang/Microsoft.
Food & platters (from $75) — Extra pizza, fruit and veggie platters, dessert trays and catering for the adults — tap through for what each one includes.
- Ice Cream Treats — $75 for up to 20 kids, then $4 each: A variety of cold treats are available for your party. This option includes one treat per child attending, up to 20 children. Our selection includes dairy free and gluten free options. $4 + tax per additional child over initial 20.
- Veggie Mezza Platter — $99: Fresh veggies, hummus, baba ghanoush, dolmas and tabbouleh served with olives and herbed feta. Serves 16.
- Fruit Platter — $99: A platter with a variety of fresh fruits, sliced and sure to make for a sweet celebration. Serves 16.
- Dessert Platter — $99: A platter with brownies and assorted cookies for your party. Serves 16.
- Chicken Fingers - Full Tray — $110: Full tray of chicken fingers. Serves 15-25. Not available for Sunday morning parties.
- Fries - Full Tray — $110: Full tray of fries. Serves 15-25. Not available for Sunday morning parties.
- Buttered Pasta - Half Tray — $110: Half tray of buttered pasta. Serves 12-14. Not available for Sunday morning parties.
- Buttered Pasta - Full Tray — $110: Full tray of buttered pasta. Serves 15-25. Not available for Sunday morning parties.
- Mozzarella Sticks - Full Tray — $104: Full tray of mozzarella sticks. Serves 15-25. Not available for Sunday morning parties.
- Stuffed Mushrooms - Full Tray — $80: Full tray of stuffed mushrooms. Serves 15-25. Not available for Sunday morning parties.
- Mozzarella Caprese Salad - Full Tray — $91: Full tray of mozzarella caprese salad. Serves 15-25. Not available for Sunday morning parties.
- Penne Vodka - Full Tray — $110
- Penne with Marinara Sauce - Full Tray — $110
The wow factor (from $25) — Cotton candy, popcorn, glitter tattoos and party-room lighting — the touches that take it to the next level.
- Glitter Tattoos — $350 + $10 per guest: Make your party extra glamorous by having your guests receive temporary glitter tattoos! During your party, one of our dedicated staff members will apply temporary glitter tattoos to guests. This package includes 30 extra minutes to make time for tattoo application!
- Cotton Candy Machine — $275: Unlimited cotton candy for all your guests — kids and adults — made fresh throughout your party. Setup, operation and cleanup included.
- Popcorn Station — $199: Unlimited fresh popcorn for all your guests — kids and adults — served throughout your party. Setup, operation and cleanup included.
- Additional Party Child — $40
- Additional Party Adult — $25
- Late-Addition Premium for Additional Party Child — $50
- Late-Addition Premium for Additional Party Adult — $35
Beer, wine & mimosa bars (from $200) — We're licensed for beer and wine in NYC — if the grown-ups are staying, wow them with a mimosa or bellini bar, a beer and wine package, or a full bar.
- Wine Package — $300: Includes up to 5 bottles plus all service fees. Excludes Champagne.
- Beer Package — $200: Includes up to 24 assorted beers from our shelf, plus all service fees.
- Custom Beer & Wine — $275: Custom beer and wine selection
- Mimosa Bar — $250: 3 bottles of Prosecco + orange juice in our champagne flutes, plus all service fees. Additional bottles available for an extra cost. Add Champagne for an extra cost.
- Bellini Bar — $250: 3 bottles of Prosecco + peach juice in our champagne flutes, plus all service fees. Additional bottles available for an extra cost. Add Champagne for an extra cost.
Drinks for the adults (from $50) — A coffee bar for the grown-ups, non-alcoholic beverage packages, and BYOB service with glassware.
- Non-Alcoholic Beverage Package — $75: Purchase a mix of still and sparkling waters for your guests, a total of 24 bottles.
- Coffee Bar Package — Priced à la carte: If you would like to pay for coffee and tea for your guests, please let us know and we will set up a tab for you.
- BYOB Service — $50: Bring your own beer and wine and we will take care of the rest — chilling, setup and service throughout your party. Light-coloured wine and beer only please; no red wine permitted.
- BYOB Plus (wine glasses) — $75: Everything in BYOB Service, plus proper wine glasses for your adult guests. Light-coloured wine and beer only please; no red wine permitted.
Goody bags (from $12.50) — Let us handle the favors — three tiers of Genius Gems goody bags, priced per guest and ready to hand out at pickup.
- Classic goody bag — $15 per guest: Includes: A Genius Gems "gem" pen, a flashlight, 3 fabric Glitter Tiles, one 5 token piece, a slap bracelet
- Deluxe goody bag — $25 per guest: Includes: Everything in the Classic goody bag and a package of Genius Gems Glitter Tiles
- Premium goody bag — $50 per guest: Includes: Everything in the Classic and Deluxe goody bags and a DIY Glitter Tile Project Set
Balloons, filled right here — We have our own helium tank in Millburn — add helium balloons for your party tables straight onto your package, no outside vendor needed. Ask your coordinator when you plan the party.
Balloon décor — Bouquets, garlands and giant numbers, coordinated with your party and set up before guests arrive.
Extra time (from $300) — Add 30 minutes, schedule permitting — usually at the start of the day's first party or the end of the last one, and typically not for the 1 PM slot. Extra time is not guaranteed: if it's essential to your party, reach out before you book so we can reserve it for you. Approved in writing in advance (not by phone). A second project during that time is a separate add-on.
- Add 30 minutes (Premier Plus) — $750
- Add 30 minutes (Premier) — $400: More building, a calmer cake moment, and less rushing.
- Add 30 minutes (Elite Drop-Off) — $300
- Add 30 minutes (VIP Glow) — $750
Extra time (from $350) — Add 30 minutes, schedule permitting — usually at the start of the day's first party or the end of the last one, and typically not for the 1 PM slot. Extra time is not guaranteed: if it's essential to your party, reach out before you book so we can reserve it for you. Approved in writing in advance (not by phone). A second project during that time is a separate add-on.
- Add 30 minutes (Premier Plus) — $350
- Add 30 minutes (Premier) — $350
- Add 30 minutes (VIP Glow) — $350

A room that's actually yours

Your party room is reserved for your group for the full party, set with tables, tablecloths and servingware before you arrive. Full-facility packages take over the whole space.

Private party rooms — A 500+ sq ft party room for Premier parties, or the whole 10,000 sq ft facility for Premier Plus and VIP Glow.
Private party room or the full venue — Premier parties happen entirely in your private party room — we bring the building, the project and the food to you. Premier Plus and VIP Glow take over everything, indoors and out.
Glow-in-the-dark room — Part of every party tour, and the star of the VIP Glow evening package.
VIP Glow evenings — Friday, Saturday and Sunday evenings, lights down, disco lights on — the whole venue glows.
Café for the grown-ups — Adult food and drinks are set up in the café so the party room stays all about the kids.
Beer & wine license — NYC is licensed for beer and wine — mimosa and bellini bars, beer and wine packages or a full bar for the adults who stay.
Bring your décor — or let us do the balloons — Your own tablecloths and themed servingware are welcome, and balloons can be added to any package (filled in-house in Millburn; by our partner Balloons To Go in NYC).

The Millburn party room — a dozen kids inside the magnetic-tile wall they built, under a Happy Birthday banner

The NYC party room set for a party — long white tables, pink balloons on every table, pizza and juice out

Parties at Genius Gems

A grinning party guest in front of foil balloon letters — The birthday face.

Nine kids waving from behind a rainbow tile wall — Every party builds something big.

Four laughing kids in party hats behind a tile castle — Party hats optional, castles mandatory.

Party leaders helping guests at the glitter-tile table — Our party leaders run every station.

A guest stretching pink slime at the party table — Slime, perfected.

The Millburn party room set with balloons and confetti tables — Millburn, ready for guests.

Good to know

Cake or cupcakes from you are the only outside food — everything else comes from our kitchen and menu. Food brought for religious reasons is welcome; just tell us in advance.
No ice-cream cakes or anything that needs a fridge or freezer.
If your cake needs to be refrigerated, tell us ahead of time so we can plan the space — our party staff usually can. Ice-cream cakes still aren't a good fit.
Balloons are welcome if weighted. Decorations go up only with the painter's tape we provide — no glue dots, regular tape or glue on the walls — and no confetti or sparklers.
Guests should arrive at the party start time — the room is being set up until then. The birthday family is welcome up to 15 minutes early.
We staff and prepare for the guest count you confirm. Once a party is paid, there are no refunds or credits if fewer kids or adults attend than expected.
Your final head count is due by the Thursday before your party. After the deadline, added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge.
Parties are for ages 5 and up — 5-year-olds with an accompanying adult, drop-off from age 6. Parties for 4-year-olds are available as a full rent-out.
Your party coordinator calls the week of the party — the Sunday before, or by Wednesday at the latest — when you'll have all your numbers. That's when food, projects and add-ons get locked in.
A planning call with your party coordinator happens at least two weeks out, so you know exactly what to expect — that's when food, projects and add-ons get locked in.

Frequently asked

Booking & timing

How do I book a party?: Right here — pick your location, package and time. Your party coordinator calls the week of the party — the Sunday before, or by Wednesday at the latest, when you'll actually have your numbers — to confirm the details and any add-ons. Extras are paid the Thursday before your event.
How do I book a party?: Right here — pick your location, package and time. Our event coordinator reaches out at least two weeks before the party to confirm the details and any add-ons, so you know exactly what to expect, and you'll have the chance for a 30-minute planning call. Extras are paid the Thursday before your event.
How far ahead can I book?: Up to four months ahead, at both locations — the calendar shows every open slot in that window. Weekend slots go first, so book early if your date matters.
How soon can I arrive?: You may arrive 20 minutes before your scheduled party. Our staff may still be cleaning up from the previous party or event.
How soon can I arrive?: You may arrive 15 minutes before your scheduled party. Our staff may still be cleaning up from the previous party or event.
How soon can my guests arrive?: To keep everything on schedule, we kindly ask that guests arrive at the party start time.
Would it be possible to book a party for a time or date not listed on the website?: Yes — email us and we'll do our best to accommodate you.
What if the birthday child gets sick?: In extenuating circumstances such as sickness or injury we'll do our best to reschedule at a mutually convenient date. As per our cancellation policy, we're not able to offer refunds for party cancellations.

Guests & head count

Are adults included?: Yes — every package includes a set number of adults (it's on each package card; Premier includes 16 adults with 16 kids). Each extra kid includes 1 more adult at no extra charge, up to the package maximum (22 kids and 22 adults for Premier). If more adults come than children, the extra adults are $25 each.
When do I need to give my final head count?: Final numbers are due by the Thursday before your party. That's when we set the room, order the food and pack the projects — Friday is too late for us to have everything ready. After the deadline, added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge.
When do I need to give my final head count?: Final numbers are due by the Thursday before your party. That's when we set the room, order the food and pack the projects. After the deadline, added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge.
Can an Elite Drop-Off party have more than 18 kids?: The Small Party Room holds up to 18 kids, so 18 is the Elite maximum. If your list might be bigger, an upgrade to a Premier party in the large party room is possible only when that room is still available — and it often isn't. If you're unsure of your count, we recommend booking a Premier party from the start.
Can I add kids or adults after the final head count?: Usually, yes: add kids in your party planner. After the deadline, added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge. Guests who arrive on the day without notice are charged at the end of the party at the extra-guest rate plus a $10 late-addition premium: $50 per additional kid and $35 per additional adult on Premier (other packages follow the same rule on their own rates).
Can I add kids or adults after the final head count?: Usually, yes. Kids added in your party planner are $40 each on Premier, VIP Glow and Premier Plus. After the head-count deadline (the Thursday before your party), added kids may need our approval (we say yes if we can staff it) and may carry a 25% rush charge. Kids added on the day of the party are $50 + tax each, charged at the end of the party. Extra adults are $25 each, whether added in advance or on the day.
What happens if fewer guests arrive than I paid for?: We staff and prepare for the guest count you confirm, so if fewer kids or adults come than you paid for, there are no refunds or credits.
What happens if more guests arrive than I paid for?: If more kids or adults come than expected, the additional guest price is paid at the end of the party — extra kids at the same-day rate ($50 + tax each on Premier, VIP Glow and Premier Plus) and extra adults at $25 each.
Can I count children as part of the adult guest number?: No — children and adults can't be swapped. If there are more children or adults than your party's initial number, the respective additional guest price is paid at the end of the party.
What if my guests stay past the end time?: We're happy when guests love the space! Families are welcome to buy tickets to stay and play. If they don't, the additional time fee is charged automatically — you have a 15-minute grace period to pack up.

Food, drinks & deliveries

Am I allowed to hire outside vendors or caterers?: We provide comprehensive in-house services and catering to keep the event smooth. Outside vendors or caterers are welcome with advance approval and a service fee — and we keep it simple: give us the vendor's business name and email address and we handle the paperwork. They complete everything, including the certificate of insurance, in a few clicks.
Can I have cake or balloons delivered for the party?: Deliveries must be on the day of the event, during business hours, and we must be notified in advance. We don't have fridge or freezer space for cakes, and we can't be responsible for delivery mishaps. Talk to our event coordinator if you'd like to drop decorations off early.
Can I have cake or balloons delivered for the party?: Deliveries must be on the day of the event, during business hours, and we must be notified in advance. We can't be responsible for delivery mishaps. Talk to our party coordinator if you'd like to drop decorations off early.
Can my cake be refrigerated?: Usually, yes — our party staff can refrigerate a cake if we know ahead of time, so please mention it when you plan the party so we can make the space. Ice-cream cakes aren't a good fit.
Do you offer kosher pizza?: Yes — kosher pizza can be ordered through us for the party at an additional cost; ask your coordinator and it's added to your order. More generally, families who need to bring in food for religious reasons are welcome to — just let us know in advance so we can plan the table.
Can adults have a drink at the party?: In NYC, yes — we hold a beer and wine license. Choose a mimosa or bellini bar, a beer and wine package, or an à la carte bar in your party dashboard after booking.

The space & the practical stuff

What are the table sizes and room setup like?: Tables are 32 in. × 32 in. and 29.5 in. tall. Typically 9 tables are used for the take-home activity and eating, with 2 more as the cake/dessert table. Elite parties include up to 8 tables plus 1 cake table. Specific layout requests are welcome in advance.
What are the table sizes and room setup like?: Bringing tablecloths? Email us and we'll send you the exact table measurements and the number of tables set for your party size. Specific layout requests are welcome in advance.
Can I hang decorations?: Yes — with the painter's tape we provide, which comes off our walls cleanly. Please don't use glue dots, regular tape or glue. Weighted balloons are welcome; confetti and sparklers aren't.
What if I leave personal party items behind?: It happens! Please pick up your items within 48 hours at the location; after that they're donated per our lost & found policy.
What is your tipping policy?: Gratuity isn't included in your party price, and tipping is never required. If your party team made the day special, tips are always appreciated. They're shared among the hosts who ran your party, and cash or card is welcome.

Let's celebrate

Pick your location, choose a package and a time, and you're booked in minutes.

Book a party — Millburn, NJ, 215 Millburn Avenue, Millburn, NJ 07041
Book a party — New York City, 555 6th Avenue, New York, NY 10011

Questions first? Email information@geniusgems.com