Note: This game works in Safari. It does not work in Chrome. Other browsers tbd.
Check out the video demo here.
For more info on my experiments with JS and CSS animations during the development of this game, check out my Medium post at https://medium.com/@adaml22/three-methods-for-animating-movement-in-js-css-579365ec0725.
Ruby version: ruby 2.6.1p33