The FORTH code for Chipwits is released in the game's 40th anniversary

Forth has been something I've wanted to learn for years now. It seems weird to me that for most stuff in old computers, you have the option of "assembly" if you want your program to be fast, and "BASIC" if you want your program to be slow, but Forth lingers along as the "medium speed" language, despite at least looking pretty high-level.

Very fast (faster than naive assembler) but not at all high-level; having to look after the stack is a bit of a pain. Writing your own FORTH is fun - it doesn't need to be in assembler - I once wrote a FORTH-like scripting language in C++.

but it's also very extendable. It's ability to slap on new control structures and DSL's is on par with Lisp. I'd say it's very low level and much higher level than the most languages simultaneously.