What music-based dungeon crawler game is this?

Solution 1:

This indie game is called "Crypt of the Necrodancer".

This game is quite new, being released in late April 2015, and has achieved very high ratings, 10/10 on Steam and 4.5/5 on Metacritic.

As you noted it's a rogue-like, (proceduraly-generated) dungeon crawler but incorporates elements from rhythm games. For instance the player cannot perform actions such as moving or attacking unless they perform the action in time with the beat of the music.