This manga is... OK, I guess.
It's got the classical "The MC made a contract with a Dungeon so now he's unable to feel guilt about killing people" deal, though, which... isn't that even worse than contracting with a devil, really? I'm not a fan of the trope.
More than that, what I like for a Dungeon story to have is some sense of the underlying mechanics.
OK, so there are Dungeons. WHY are there Dungeons? What does the System get out of setting up Dungeons? What is their role in the ecosystem?
With something like Dungeon Meshi, you get the sense that the author knows and cares about the answer to this question. You get hints that the Dungeon was created in some sort of calamity, sort of like a really big haunted house.
With this? A bit too early to tell, but unless the Healer Girl turns out to have been the real MC all along, it's not looking good.