Loop Hero! It's free on Epic right now and I've been really enjoying it! A nice blend of procedural generation, deck building, and roguelike allow it to be a very rewarding and engrossing experience overall where I feel I'm consistently progressing.
I still haven't been able to beat The Lich yet, but little by little I'm knocking his health down that much further to make the loop (heh) feel rewarding!
I definitely had fun with it, and I finished it just as I was getting tired of it, so it was the right length. Got it off another EGS giveaway a couple of years ago, I think.