HTML5 and JavaScript Game Development Competition in just 13kb – created by @end3r. Runs for a month: August 13th to September 13th. #js13k

It's not js13kGames-specific news, but still on topic of online competitions: Gamedev.js Jam 2021 starts today, April 13th, and offer Web Monetization as one of the two optional categories.

The other is Decentralized, and there's a whole bunch of cool prizes to win – from software licenses, through cash, crypto, to hardware devices, worth a total of $20k. It is hosted on Itch.io, and runs till April 26th, so there's plenty of time to build something cool!


The js13kGames 2020 t-shirts, pens, and stickers were sent out to their winners, and people are already starting to share the pictures wearing their new swag.

There's a dedicated photo album we'll be adding all the published selfies – make sure to let us know if you happen to do exactly that. On Twitter, we use #js13k hashtag to mark such media.


The Mozilla Festival 2021 is slowly coming to an end, and so we decided to recall previous MozFest Arcade experience and prepare a totally subjective list of five games that utilize Web Monetization API you can play right now and support its creators.

In October 2019, when Mozilla Festival was held in a physical location of Ravensbourne University in London, we’ve partnered up with the Grant for the Web folks to create and run MozFest Arcade – a booth hosting nomerous Web Monetized games from both our own Enclave Games studio and the js13kGames competition. People could play the games at the booth, and see how micro amounts of money were streamed directly into the wallets of the creators in real time.

Let’s do the same, but online! Check out the list of five interesting games that are Web Monetized:


Created by the Piesku team for the first year of the Web Monetization category in the js13kGames 2019 competition, Backcountry takes you to a Wild West themed place where you are tasked with finding the bandits and getting paid for bringing them to justice.

Web Monetized users can change the appearance by picking various hats for their characters. The game ended up on the 3rd place in the monetization category and was showcased at the MozFest Arcade booth in London.

Relic Splatter

Relic Splatter was submitted to the Web Monetization Challenge run by Björn Ritzl from the Defold foundation.

Quoting My top 5 games from The Web Monetization Challenge 2020 blog post:

Relic Splatter is definitely my favourite with cool idea, nice graphics, smooth gameplay, and a whole lot of juiciness. I really liked splashing colorful stuff all over the place, and the idea of using a gun as a jetpack as well. Paying Coil members get help finding the relics.


Ninja vs EVILCORP is a game created by Rémi Vansteelandt for js13kGames 2020. The game won both the Web Monetization category itself, and the whole competition in general.

Quoting Summarizing Web Monetization category in js13kGames 2020 blog post:

The entry that got the first place based on how well the feature was implemented, Ninja vs Evilcorp, offers… the lowest possible difficulty level for Coil members: Practice. Isn’t this brilliant? If you’re lazy (like me, especially lately), or tired, or have only a couple of minutes to spare, but you still want to try the game, you can go straight through it without worrying that you’ll lose immediately. I’m guilty of lowering the difficulty levels of way too many games I’ve played, only for the fact that I’d like to enjoy the story behind it.

Sushi Party

This is basically a multiplayer Snake game, a Slither.io clone, but perfectly executed, with cute graphics, and no adverts for the paying Coil members.

The best part? You can eat loads of sushi!

Flood Escape

Fifth game is going to be an ordinary shameless plug, because Flood Escape is our own creation. It is placed on the list, because it was one of the first games, if not the very first, that was Web Monetized.

You can expect more games coming from us in the next weeks and months ahead, and all of them will for sure implement Web Monetization API in some (hopefully) creative ways, which we’re gonna share through blog posts in detail.

Gamedev.js Survey and the Jam

Two extra things I wanted to mention are Gamedev.js Survey and Gamedev.js Jam. The Survey (“to learn about the current state of the HTML5 Game Development in 2021”), being part of our Grant as well, is coming to an end – we’re closing the form today, March 18th end of day, and will publish the results after a week.

The Gamedev.js Jam 2021 is the second edition of the online competition for HTML5 game developers, and it will run between April 13th and 26th, hosted on Itch.io. It’s a perfect opportunity to build some nice monetized games that might be featured in the next such article! We do plan to announce prizes, the Web Monetization category itself officially, and more in the coming days, so make sure to follow the competition’s Twitter for updates.


If you follow the competition for long enough this is absolutely no surprise – printing of the swag from js13kGames 2020 was delayed a few times, similarly to the previous years. It’s finally done though, and all the packages were already shipped!

We have a new t-shirt design every year thanks to Ewa, and offer different gadget as well – this year’s one is a pen. The package comes with a bunch of stickers: both our own (js13kGames, Enclave Games, Gamedev.js) and from our Partners.

We had to quickly print the compo ones as I thought we still have a lot of them, but apparently they ran out last time – I ordered a bunch and put three in every package instead of one or two.

The packages, each containing a t-shirt, a pen, and a whole bunch of stickers (including a whole collection depicting notable entries from previous years thanks to Sascha from eBay) were sent out – if your entry ended up in top 100 overall results, top 15 WebXR category, or you were an Expert, expect the package coming your way.

The tracking details were emailed to everybody interested, so make sure to keep an eye on them as some local post offices or customs services might take longer to process it than others.

If you do get the package already, please post a selfie! When sharing on Twitter, make sure to use the #js13k hashtag. We have a long tradition of having a photo album of cool people wearing js13kGames t-shirts all over the world from every single year, and would like to keep that going this time as well, thanks!


We're working on the new website (yay!), and I'm really hoping this time it'll be ready for the start of the new edition of the competition. We wanted to ask you three short questions about it – please fill out this survey and give us your feedback.

If everything goes well, we should be able to publish the first version of it on GitHub soon and ask for your help building new features – stay tuned for more info if you're interested.


There are two interesting video materials about last year’s competition that are worth spending some time on: showcase of all the 36 entries from the Web Monetization category recorded by Jupiter Hadley, and overall top 20 best games with their source code explained by Ania Kubów prepared for freeCodeCamp.

Showcase of the Web Monetization category entries

Jupiter Hadley, who is a well known YouTuber gameplaying competition entries for a few good years now, went through all the Web Monetized games, so you can get an overview of the level of quality they represent.


Out of the 36 games submitted to the Web Monetization category in 2020 supported by the Grant for the Web there’s a bunch that ended up in the top 20 overall results, including the winner of both: Ninja vs EVILCORP by Rémi Vansteelandt.

20 award-winning 13-kilobyte JavaScript games

Ania Kubów did an awesome job making the video containing the best entries from the competition, along with explaining some of the most interesting coding tricks the authors executed.

You’re going to see 20 great examples of code from 20 insanely talented developers.


It was either the authors themselves explaining those, or Ania reading their notes – the video is more than one hour long, but worth every second spent on watching! It was published and sent as a headline by Quincy Larson to the freeCodeCamp community through their newsletter.

Remember that the source code of all the games submitted over the years is available on GitHub, so you are free to study and learn from it. Don’t forget about the Post Mortems developers write as well, where they share their lessons learned of what went good and what could’ve been improved.


We've published a showcase of all the games submitted to the Web Monetization category in the js13kGames 2020 competition, which ended up being a total of 36 entries.


Make sure to read Summarizing Web Monetization category in js13kGames 2020 published back in October where we went through some details of running the competition, examined top 10 entries, and shared our lessons learned from the second year this category was organized.


It was the second year when we had Web Monetization category in the js13kGames competition, and we can already see the progress in how the developers implement extra monetization features.

First of all, the number of entries submitted this year is lower than in 2019, both to the category (48 in 2019, 36 in 2020) and overall (245 vs 227). You could imagine people would have more time to actually code new games given the unusual situation with the pandemic while mostly staying home, but I received a lot of feedback that it was actually totally the opposite.

Many devs were affected on various levels, from getting sick, having difficult situation in their life, to blatantly being fired from work, so “making games for fun” wasn't a top priority anymore. From the huge amount of tweets sharing development progress using #js13k hashtag this year you could imagine we'd end up with another record number of entries, but it wasn't the case after all. I've received way more messages this year saying that someone couldn't finish and submit their entry than in a couple of previous years combined.

Ok, now that we have this cleared out, let's focus on the entries. There are a few “false-positives” in those 36 submitted games, which didn't happen last year. One or two entries don't have any monetization at all, a few only added the meta tag – it's unclear if the reason behind it was getting free Coil memberships, or maybe something else.

Top entries

Entries with the proper Web Monetization features implemented seems to have those better integrated into the gameplay, compared to previous year. In 2019, this concept was brand new, and it revolved around adding bonuses, while in 2020 there was a few good, well executed ideas.

Of course those might seem “obvious” after you learn what they were, but this have to be discovered through experimentation first, right? Let's look at the top10 best entries from the Web Monetization category this year:

1. Ninja vs EVILCORP by Rémi Vansteelandt

2. OFFICE 404! by Tricsi

3. Symmetry Not Found by Sirxemic

4. RESCUE not FOUND by David Brad

5. Johnny Smiter III by Paul Brunt

6. The Legend of Yeti-404 by Richard Munn

7. Track not found?! by Xem

8. Big Movie Hacker by Daniel Cohen

9. Ned Snow by Juankz

10. Universe Not Found by Cameron Manavian

The entry that got the first place based on how well the feature was implemented, Ninja vs Evilcorp, offers... the lowest possible difficulty level for Coil members: Practice.

Isn't this brilliant? If you're lazy (like me, especially lately), or tired, or have only a couple of minutes to spare, but you still want to try the game, you can go straight through it without worrying that you'll lose immediately. I'm guilty of lowering the difficulty levels of way too many games I've played, only for the fact that I'd like to enjoy the story behind it.

It's the exact opposite to Dark Souls where dying dozens of times because of the insane difficulty level IS the gameplay, or Flappy Bird type of games where you can lose after a second and you repeat and repeat and repeat until you get it perfectly right, and then the single gameplay lasts for, maybe, 30 seconds total. This approach is of course totally correct for many players, but others will find the slow pace with no distractions and unnecessary dying simply more enjoyable.

The second place was Office 404!, where monetized users were offered a discount when buying items – this made the game slightly easier without affecting the gameplay too much. If you're not a paying Coil member, it takes only a little bit longer to buy stuff. The feature was balanced enough to not ruin the core game mechanics, and offered something extra on top of it.

The third place was taken by Symmetry Not Found, a game where you solve puzzles by moving shapes to achieve perfect symmetry – active Coil membership doubles the available time a player have to solve each puzzle. Again, it makes the game easier to enjoy without too much pressure from the time running out. Lower difficulty level for casual experience, just like in Ninja vs Evilcorp, but adjusted to the different gameplay.

In the Rescue Not Found game the extra monetized feature goes in the opposite direction – you can decide if you want to have a level 2 crew member from the start or not, since it comes with slightly higher difficulty level as you might end up with more challenging tasks from the beginning. It feels like you can have a head start, but it comes with a price, so you have to know what you are doing.

Fifth game in the category is Johnny Smiter III, which is actually a fourth installment of Johnny in the js13kGames competition by the same author, who constantly plays with various game mechanics and styles. In this episode, the main character can get some help from The Great Mage Coil, who will assist them in the journey and allow to see sacred numbers within the shadows.

The improvements

Make sure to check other entries from the category, as you'll find more interesting takes on Web Monetization. From those in the second part of the ranking one main issue arise – the bonus is not clear or visible enough. Many entries mention this only on the entry's page, and not in-game, which might be confusing if someone jumps into the gameplay directly.

Another case is bonuses that you don't get immediately – extra level at the end of the game is something not too many will actually experience, even more if it's a surprise to the player. Clearly stating what is the difference between the regular gaming experience and Coil-boosted is something more games have to incorporate if they want to be successful.

The summary

Make sure to check the top5 picks from the experts, and best entries from given criteria as well. The voting app is full of comments from the developers themselves on each other's games. Lots of positive feedback from the experts can be found on the pages of given entries as well. The Web Monetization category got more expert comments per entry than the competition average (4 vs 2) on purpose to award developers who decided to participate.

I also decided to offer a Nintendo Switch for the best entry on top of free Coil memberships, since WebXR category had hardware prizes in the past few years, and it made sense to award something “big” here as well, beside standard software licenses. This combination of easy to get, guaranteed prize for everybody and something unique for the best games seems to work the best.

Last year's Web Monetization category was supported by Coil directly, while this time it was covered by the Grant for the Web program, for which I'm really thankful for – it would be a lot harder to run the competition and spend months of work on it without their help.

Overall, I think it went great, and I can't wait for 2021 as it'll be a tenth edition. I'm excited to see what people will come up with after another twelve months of experiments with Web Monetization!


FOURFOLD by @saud

ROAR by @stas