I think you can make it as challenging or not challenging as you want. Just implement a simple Forth or Lisp in Lua and make a cute little game with Love2d or even just a simple text game.

Maybe I expect too much from people but like at least being able to write a simple tree-walking interpreter is basic computer science education and who hasn't tried to make a game at least once?

The problem is more that some people just like sharpening the saw and some people like cutting down trees. Both are valid. Some people get really into programming languages and tooling but never ship any product or vice versa. But people need to be skilled enough to do both.

The crossover of language design/implementation and game development made me assume this was either a Jonathon Blow (Jai, Braid, The Witness) or Bob Nystrom project (Game Programming Patterns, Crafting Interpreters, 'Is There More to Game Architecture than ECS?' [1]).

Either way, given the time constraints and requirements I'm expecting a lot of text adventures and rogue-likes.

[1] https://www.youtube.com/watch?v=JxI3Eu5DPwE

Easy, create a DSL that represents dialogue in a visual novel style game. Add some branching, looping, and variables, maybe some labels for jumping to and you’re good. Tada! You’ve basically reinvented Ren’Py.

A programming language could be as simple as a domain-specific-language done in a JSON format. It could just abstract away a bunch of thing, and most of the logic would just be in your "game engine".