If youve played any rogue-likes before you will be familiar with the randomness of each attempt to get to the final boss. Each try contains a different dungeon layout. Within that random layout each room contains a random assortment of enemies, shops, chests, stat and ability and health pickups, level modifiers and secrets, of which there are quite a few. On top of that is the rhythm-action mechanics meaning you can only shoot in time with the music and Awe Interactive have provided a great rock soundtrack which brings the whole game together quite nicely.
Source: N4G PC BPM: Bullets Per Minute The Verdict | The Reticule