I had some ideas for word games based on semantic distance, it will be an interesting problem to see if I can do this performantly in the user's browser. I think Semantle precomputes data for each day's puzzle but I want it to calculate it dynamically.
It would be cool to make it multiplayer as well, but I've never tried to make a multiplayer game before, it's probably annoying. Maybe there could be local multiplayer or against the computer to begin with.
I've also been slowly working on a web-based text adventure puzzle game.