After playing this game, came to my mind that maybe if the developers of this game tried to make a dungeon crawler game, it would work.
I don't mean making a diablo like game, where you need to keep getting new equipments and all that stuff to progress.

Combat wise, with the levels and skills system, weapons unlocks and upgrades, and also dungeon maps that may change as you replay the runs, would probably be a interesting game to play with. And I mean it. I managed to keep playing this game until I unlocked all the skills, because the combat itself is great.

Nothing stops such a game from having a deep story, though, but I believe not making it as repetitive as it is in this game wouldn't be a bad thing.