here's my summary of wher ei am at with CSS anbd JS animation. I'll attend the developers meeting on the 24th to discuss, so please get your questions, queries and complements ready.
so far as animation is concerned I've almost got the core functionality worked out it just has to be turned into a road map with slime test cases. I may look at
https://monday.com/ to manage things, unless there is a good open-source alternative.
all i have left to do is add a path to my CSS key frame animation and look at switching the animation styling dynamically via JavaScript. you couldn't write much a game just using CSS with no javascript and besides the easiest way to add CSS animation is via a javascript shim. A shim is a good tried tested debugged implementation and saves reinventing the wheel. there are also some things you can't do with CSS eg. morphing between shapes.