I love the web audio API. I've been making a game where the theme is "I don't do art" so my assets are CSS, emojis, and manually made sounds using frequency and sinewaves and such. The one lesson I learned the hard way is that if you run a full-volume sine wave long enough you can permanently destroy your laptop speakers.
Reminds me of DOS terminal games like Rogue and ZZT which used ASCII characters to draw everything. I hope you post it once it's ready
Don't hold your breath. It'll be rudimentary. I'm making it for my own joy and learning, but will probably publish it by EOY.