Rating: 6/10

One Deck Dungeon is a fairly straightforward and mechanical dungeon crawler. It's kind of relaxing to go through, but the interesting decisions tend to be few and far between. The game is very portable, and setup/teardown can get pretty fast with practice. I would only play this in lieu of other cooperative games on account of its small box size and low weight, especially because it can play for far longer than 30-45 minutes without lots of practice from all group members.
One Deck Dungeon includes a campaign mode which isn't really worth paying any attention to.