I saw this in my feed reader and I was intrigued:
> kartoffels is a game where you're given a potato and your job is to implement a firmware for it
You can play it online, or via `ssh kartoffels.pwy.io`. You implement the solutions in no_std Rust, and upload them to the game, where I assume it runs them (I haven't tried yet). Interestingly the tooling produces a binary for a custom riscv64 target, not Wasm as I was expecting.