A lot of Death Must Die - basically a horde survival with Hades-like god boons and Diablo-esque equipment. It’s addicting

So many good games already mentioned! I would add Arcanum: Theory of Magic and Progress Knight (any variation beside the OG, like: 2.0, Reborn, Quest)

I use Playnite.

Back in 2019 I wrote a small CLI launcher in Rust (rusteam on GitHub). At this point it has barely any features and is poorly written, but I have plans to return to it.

Shattered Pixel Dungeon, Slay the Spire and a bit of Nikke: Goddess of Victory on the side.