Ok so I had some free time and wanted to play some more with HTML+Canvas from Kotlin-js to animate the "Jurassic Jigsaw" puzzle in the browser. After reinventing a few wheels and breaking probably a hundred good practices when it comes to HTML animations, I ended up with something that sort of works.
https://jakubgwozdz.github.io/advent-of-code-2020/day20/ (you can put your own input too)