I have been working on a ray-caster for the NES [1].

Ray casters are fun because they aren't that computationally expensive, so it can be a fun way to bolt on 3D to a system that really doesn't support it.

[1] https://youtu.be/2wPT_UD6Ptc I'm still learning how to program for the NES so it's super buggy. I was trying to do the thing that Elite does by having a bunch of different lines as sprites and using that to represent vectors with... interesting results.