April 13th - 26th 2021

Gamedev.js Jam 2021

Let's build Web games!

Check the Winners!

Main Partners

NEAR Protocol Protocol Labs Grant for the Web


eBay Poki Paras marketplace OP Games Coil
Supporting Partners
Enclave Games js13kGames Web3 Gamedev School


The Jam runs for 13 days: between April 13th and 26th 2021.


A globally available online event hosted at Itch.io.


Have fun building games and win some prizes at the same time!

Gamedev.js Jam celebrates Web games - build an HTML5 game within 13 days of the jam on a given theme, it runs between April 13th, 5 PM CET and April 26th, 5 PM CET 2021. Also, there are prizes!

Check the Winners!

Theme for this year's jam is: Mirror. Remember that your entry will be judged based on how well you implement the theme, but you can interpret it however you like.

Join us no matter your skill level - this game jam is a perfect opportunity to create your very first game, or build a prototype for your next commercial hit. Almost two weeks of development time should be more than enough!

You can use #gamedevjs hashtag on Twitter to share your progress, ask for feedback, see what others are building and hopefully help them out if they need it. There's also a Discord server for direct communication!

Check out all the editions to see how the competition evolved over the years: 2024, 2023, 2022, 2021, 2020.

This Jam is organized by Andrzej Mazur from Enclave Games, creator of the js13kGames competition.

Gamedev.js Shop


There are two categories in the Jam: Web Monetization and Decentralized. Both are optional, and the entries submitted to those categories will be judged separately by the panels of experts.

See the Results

Take part in the Web Monetization category supported by the Grant for the Web program if you'd like to implement Web Monetization API in your jam submission.

Take part in the Decentralized category if you'd like to implement any of the decentralized technologies in your jam submission. Those could be from NEAR Protocol or Protocol Labs (IPFS, Filecoin, etc) if you'd also like to complete any of the challenges, or it can be something else entirely.


Challenges are part of the Decentralized category - there are three to pick from, and you are free to take on any of them, or all at once.

Each and every challenge offers unique prizes, so make sure to check those out.


There are three levels of prizes: for all the entries, for specific categories, and for challenges.

Overall prizes

Those prizes will be given to the best entries of the overall ranking on Itch.io:

  • Top15 entries: pen and notebook from Poki Shop
  • Top10 entries: physical surprise goodies from eBay
  • Top5 entries: mobile charging station, tee, socks, mug from Poki Shop

Web Monetization category prizes

Those prizes will be given to the best entries selected by a panel of experts:

  • 1st place: $300 cash
  • 2nd place: $250 cash
  • 3rd place: $200 cash
  • 4th place: $150 cash
  • 5th place: $100 cash

Every entry can win only one cash prize and one Coil membership per team. Cash is wired through PayPal or bank wire, taxes are paid by the winners.

Decentralized category prizes

Those prizes (including challenges) will be given to the best entries selected by a panel of experts:

  • 1st-10th places: Ledger Nano S
NEAR Protocol challenge prizes
  • 1st place: 225 NEAR (~$1500)
  • 2nd place: 175 NEAR
  • 3rd place: 125 NEAR
  • 4th place: 75 NEAR
  • 5th place: 25 NEAR
  • 6th-10th places: 15 NEAR (~$100)
Protocol Labs challenge prizes
  • 1st place: 8 FIL (~$1500)
  • 2nd place: 6 FIL
  • 3rd place: 4 FIL
  • 4th place: 2 FIL
  • 5th place: 1 FIL
  • 6th-10th places: 0,6 FIL (~$100)
Paras challenge prize
  • 1st place: $500 cash

Winners will also be promoted via our Twitter, on the gamedevjs.com website, and in the Gamedev.js Weekly newsletter.


Two panels of experts for Web Monetization and Decentralized category entries.

Web Monetization experts

Björn Ritzl
@bjornritzl | defold.com
Product Owner and Board Member of the Defold Foundation, overseeing development of the free and source available Defold game engine. Worked with mobile game development since before the smart phones. Loves old school games and roguelike games (hosts the Rogue Basin wiki). Strong believer in the power of open source development with more than 150 open source projects on GitHub.

Ania Kubów
@ania_kubow | youtube.com/aniakubow
Ania is a Software Developer and YouTuber who loves to teach JavaScript and React by building all sorts of retro online games.

Nathan Lie
@feraltc | coil.com
Nathan is a Software Engineer at Coil who considers himself a gamer first and an engineer second. He's been working with and on applications using Web Monetization for the past year, and is eager to see the intersections between Web Monetization and game design this year!

Ewa Mazur
@mypoint13k | mypoint.pl
Graphic Designer, mom and wife. Open source and mobile games enthusiast. Making game designs for Enclave Games, t-shirt designs for js13kGames, writing inspirational posts and tutorials on Tutsy and making cool things for children at MAMAdesigner. Loves taking photos, drawing icons, and spending time with her family.

Abiyasa Suhardi
@abiyasasuhardi | abiyasa.com
Full-stack JavaScript & indie game developer, software engineer at eBay, co-founder of twindly. Love travelling, food, and sketching.

Joep van Duinen
@joepvduinen | poki.com
Joep leads the game developer operations team at Poki, the number #1 platform for play on web. Poki is on a mission to create the ultimate online playground: a place where kids of all ages and game developers come together to play and create. Reaching more than 30M monthly active users worldwide they're market leaders on web.
They help a growing 300+ game developer community - including Kiloo (Subway Surfers), Hipster Whale (Crossy Road) and Colin Lane (Dunkers) to achieve success on web. Here's more information about how game developers can get their html5 games featured on Poki.

Decentralized experts

Paul Gadi
@polats | outplay.games
Paul is CTO / Co-Founder of OPGames, focused on helping game developers successfully create decentralized games. He also leads the KERNEL Gaming Guild, a fellowship of the most talented builders in Web 3. He loves exploring the intersection of new technologies with game design, and believes that decentralization and shared virtual economies will revolutionize how we play games.

Dietrich Ayala
@dietrich | metafluff.com
Dietrich leads developer onboarding and ecosystem support at Protocol Labs, growing adoption of their protocols through developer experience, browser integrations, and strategic collaborations. Before Protocol Labs, he spent over a decade at Mozilla building browsers, shipping a smartphone OS and running programs to scale devrel globally.

Johnny Matthews
@_johnnymatthews | johnnymatthews.dev
Johnny is an English-born Canadian with an addiction to Yorkshire Tea and Timbits. He runs documentation and developer education at Protocol Labs.

Austin Griffith
@austingriffith | austingriffith.com
👩‍🎤 Builder on Ethereum

Aliaksandr 'Sasha' Hudzilin
@aliaksandrh | humanguild.io
Aliaksandr studied business at UC Berkeley, worked in investment banking under Frank Quattrone, and spent 4 years selling and marketing MuleSoft and MemSQL products.

Vlad Grichina
@vgrichina | humanguild.io
Vlad started his career as a professional TopCoder competitor and worked on mobile apps since 2009. He founded a 15 person mobile dev company and worked 3 years at Google on the Play Store.

Rahmat 'Riqi' Albariqi
@hdriqi | paras.id
Founder of Paras. Have been in the crypto space since 2017. Won multiple hackathons and bounties in web 3.0 ecosystem. On mission to humanizing the blockchain.

Experts will judge the entries through a voting period between April 26th and May 3rd.


Links from around the Web that can help you build your game for the Jam, especially for the new Web Monetization and Decentralized categories.

Feel free to suggest more materials if you have something solid to share.

Submitting your entry

Submit an HTML5 game between April 13th and 26th 2021 through the Itch.io platform. It can be a solo submission, or a team effort. You can even submit more than one entry if you want to.

Voting on entries

Voting will be open to all who submitted a game, and will happen via the Itch.io platform for a week right after the submission period ends - between April 26th and May 3rd.

Games will be voted on based on a given criteria: Innovation, Theme, Gameplay, Graphics, and Audio. The Overall ranking will be based on the summary of those.

Following the rules

The short version is: anything that can run on the Web in a browser without extra plugins is considered a valid jam entry. It's highly advised you create new content for the jam - submitting your old demos or already finished projects makes no sense.

If you have any questions or concerns please ask at the Community forums or join our Discord server.

Gamedev.js Survey 2022

Gamedev.js Survey 2022

Gamedev.js Survey 2022 is over, and the Report was already published! If you participated and submitted your answers - thank you! Feel free to view and use the results of the current state of Web Game Development in 2022 as long as you credit and link to the source.

Code of Conduct

All participants and judges of the Gamedev.js Jam are required to agree with the following code of conduct. Organizers will enforce this code throughout the online event. We are expecting cooperation from all participants to help ensuring a safe environment for everybody.

Gamedev.js is dedicated to providing a harassment-free competition experience for everyone, regardless of gender, sexual orientation, disability, physical appearance, body size, race, or religion. We do not tolerate harassment of competition participants in any form. Competition participants violating these rules may be sanctioned or expelled from the competition at the discretion of the competition organizers. TL;DR: Be excellent to each other. For more details see Berlin Code of Conduct.

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