This is how roguelikes should work not only on mobile phones but desktop computers too. User interface 10/10, graphics 10/10, audio 7/10, gameplay & balance 9/10. Very well done.
Stealth is interesting but small part of the game, I think you can get more out of it by making it more useful. Sneaking would be more satisfying if monsters couldn't hit you in the same turn they go into alerted state, for example. They also wake up rather easily, too soon for sneaking to be interesting. In case powering up stealth makes it too easy I'd just add more monsters.
I agree with most other people square-bound level design was better. The new layout requires to many touch-screen gestures just to decide where to go next, constant need to zoom in and out makes it pretty inconvenient. There was also a feeling of satisfaction when you knew you cleared the whole floor, I think that was more valuable than whatever it is we gained with the new design.
It might be interesting tactical addition if the attack after waiting a previous turn is more likely to hit or make more damage. Pausing before attacking would work like some kind of "focus", with the effect similar as using doors, only this would use up your turn which seems to be adequate trade-off.
Different sections of the dungeon cry for different background music.
