Skip to content
Go to file

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time

PULSE - My JS13K 2016 entry

Post mortem

Last year when I developed about 60% of my game, I inadvertently formatted my Mac and had no commits pulled to the repository. So I was unable to submit my entry due the lack of time to remake the whole game. Big lesson here kids, always use a version control as a backup and frequently pull your code to the remote rep. You'll never know when you're going to screw things up. ;) But I learned a lot about JS/HTML game development and it was fun (while it lasted). So I decided to enter at 2016's edition.

Unfortunately, this year I couldn't allocate too much time to develop my game. I had a couple of hours on each day of the weekend and probably would steal some sleeping time. So I needed to be smart and come up with a game that could take advantage of already-made stuff.

First was taking ideas for the game. Theme: Glitch. Oh boy. Besides the obvious screen glitches, how would I come up with a game about glitches? Went to Ferry Halim's Orisinal site to check if any game could fit the theme and so I found one: It is a quite simple game and enjoyed a lot playing it. Especially when I kept trying to break my own top score. All I needed was to insert a "glitch" on it 😉.

And so I started. First, I took Ayman's js13k starter to save time setting up the build process and developing the initial RaF/render/update bootstrap. Decided to follow a class/object approach with some kind of observable/event architecture, but it soon revealed a not-so-good decision especially when you dealing with a limited size. And, believe me, you can fill up 13Kb of code very quickly. Even compressed.

Not entering into many technical details, there's this general game object that is going to be inherited by the rest of the game entities: Game, Scene, Player, etc. Basically, it has two main methods (update and render) which calls every event registered by the inherited classes. By the end of development (and after a code re-factor), I circumvent a bit this approach just to get things done 😇.

Next, the player class Added a lot of entity states on the update/render because of the "pulse" and explosion and listeners for the mouse/touch events.

Last night finally I was able to add swarm behaviour to those pesky enemies #js13k

— Marco Fernandes (@marcoffernandes) 6 de setembro de 2016
<script async src="//" charset="utf-8"></script>

For the enemy movement I would like them to have a kind of a flock behavior so I searched and found this: It was perfect and it followed the class approach I was using. So, in a couple of hours, I was able to integrate it on my game and see the result. Beautiful!

The Swarm

Last night finally I was able to add swarm behaviour to those pesky enemies #js13k

— Marco Fernandes (@marcoffernandes) 6 de setembro de 2016
<script async src="//" charset="utf-8"></script>

Quickly I had a playable "prototype" and ready to do some tests before implementing better graphics and sound.

Tests, tests and more tests. Probably this was where I spent most of the time allocated to the game. To get a balanced mechanic and a nice learning curve you really need to test a lot and give others to test and receive feedback. As a result of the tests, I had to differentiate some vars on the mobile and desktop because on mobile it was a bit harder (a lot harder according to one tester). So, for example, on desktop you get a maximum of 200 boids, while on mobile you just get 100. If I ever build an online leaderboard, I need to remember this!

Tests and consequent code tweaks took more time than I expected. And after that I finally realized that the chosen architecture did took a lot of valuable bytes not leaving enough for, at least, sound effects. Did a code re-factor but without stepping out of the original architecture. More time spent. Soon I was on the last weekend before the deadline.

I was still missing better graphics and sound but no time. So I just grabbed a nice palette from, added a simple particle explosion ( for the player, chose a small font and submitted the game.

Nowadays I really regret not taking some time from my sleep to include some sounds and some web-gl filter which I believe it would give the game a better experience but I'm really proud of the result. Especially considering that this was my last completed game in +20 years! Yeah, I'm that old. My last completed game was a platformer written in Turbo Pascal for MS-DOS 😎.

Next year I'll surely participate again.


⚡️ Check live game here ➔




No releases published


No packages published
You can’t perform that action at this time.