One of main differences with Pico-8 is that Tic-80 supports many more programming languages.

You can write games in Lua, Moonscript, Javascript, Ruby, Wren, Fennel, Squirrel, Janet and even Python.

Or use anything that compiles to WASM. I've recently created my own bindings and a template for building Tic-80 games in Nim[1]

[1] https://codeberg.org/janakali/tic80-wasm-nim

Oh that certainly is interesting. And I've been looking at nim recently, so I'll give your project a look too! Thanks for sharing!