It's all handwritten js, lots of trying the game and figuring out what's fun, what's not. I don't even use a bundler, right click / show source will show the code I wrote. I made an apk for it and added a small deploy script that ssh to my server and pushes the code. The code is written with webstorm, but you could use anything. I've asked mistral AI for help when it came to making procedural sounds, the rest is just a lot of trial and error. I have a small ui to make levels and icons that's also handwritten.