DEVIL BLADE REBOOT - cool, high-effort SHMUP remake, fun and really nice 240p graphics
https://store.steampowered.com/app/2882440/DEVIL_BLADE_REBOOT/

Sublevel Zero Redux - Descent-like 6DoF FPS with roguelite elements, really fun and satisfying weapon options and comes with VR support which I also recommend using if you have a headset, that's how I played it and it was lots of fun
https://store.steampowered.com/app/327880/Sublevel_Zero_Redux/