I shipped a neural-network opponent into the browser: no backend, no accounts, 120 ms per move

I have a side project: a four-in-a-row board game where the opponent is a neural network I trained myself. It has been on Google Play for a while, and last week I shipped a browser version of it. The interesting constraint was this: the browser version had to be a folder of static files. No backend, no database, no serverless functions, no analytics, no accounts. Partly to keep hosting at the price of a shared plan, partly because a game that phones home to score your moves is not a game I want…