Look at anything from publisher New Blood Interactive on Steam for a starting point. Mostly retro style FPS from differing eras, but there are a few other game types. Plus you'll struggle to find any that don't have thousands of user ratings in either very positive or overwhelmingly positive brackets.
Gloomwood (first person stealth) and Fallen Aces are a couple of gems still in early access.
Gloomwood (first person stealth) and Fallen Aces are a couple of gems still in early access.