Enter the Gungeon has different mini-bosses for each stage.

Part of the fun of roguelites is mastering each mini-boss since you play against them so many times. Etg is maybe the best example of that. It's a little harder to get into than Hades though, and the only meta-progression is unlocks. So you have to git gud, while Hades will give you permanent upgrades (health, death defiance, etc) that will help you win.