>>1536437 (OP)Considering it's from the programming thread it could be literally anything, even completely custom.
Looks like 128x128 at a glance which could point to being a PICO-8 demo, but idk.
Ask in /dpt/. The only way to know for sure is if someone actually knows how it was made, and that's the only place you know for sure. Refusing to do so knowing this is intentionally making it harder for yourself.