I built a crappy scripting language. The language itself is nothing special. Vaguely ECMAScript. But it was a ton of fun to _evolve_ the language and runtime system over the span of ten or so years.

I have my collection of scripts in that language, some of which were in regular use for a time, and I wanted the changes I made to be as backwards-compatible as possible. Those were some really fun design challenges. Like: "how do you retro-fit a module system into a language that essentially started out with PHP-style source transclusion for re-use?".

I made a game engine called ZZ Zero (which is a ZZT-like game engine, and runs on DOS). There is no game other than an example.

[0] http://zzo38computer.org/prog/zzzero.zip

I've made https://sprig.land, a webgpu-based game engine and have plans to transpile the whole thing into a new visual scripting language I'm inventing but I'll eventually share it and do want to make games with it.

You might enjoy following https://mastodon.gamedev.place/@lisyarus, but he does ship games.