Doom (1993)
This plus Doom 2 for the massive amount of mods available.
Speaking of mods, if you haven’t already played it I highly recommend My House.
Nier Automata. Perfect story wise, gameplay wise and replayability wise.
Currently playing La Mulana. Great level design and puzzles that require a bit of out-of-the-box thinking. It’s easily one of the best Metroidvanias I played in recent years.
I checked my steam library out of curiosity and I have this game. I’ll have to try it out on my steam deck.
Cool, it’s quite cryptic though especially at the start. My advice is to read through the manual and don’t be afraid to read some non-spoilery guides for general gameplay tips. On the other hand, solving a puzzle feels really rewarding because of this.