I've been playing it obsessively since it came out, the earlier stages of the game can be a bit of a grind (ie perhaps a bit easy) but as you ascend into the higher levels of the dungeon it will demoralize you!
there's also a neat multiplayer component to it which allows you to request someone else to come into your dungeon to save you if you've fallen. Unfortunately for me I don't have any friends on my vita who play this, so if anyone out there wants more PSN friends, maybe we could post our usernames on here.
PSN: Outbackpenguin