Music and graphics were both good. Gameplay was solid enough, but maybe felt a little slow in the beginning.
Also, not sure if this is a bug or a mechanic I don't understand, but sometimes I get mutations from picking up the enemy drops and sometimes I don't. Made it all the way past the first boss before I got my first one, then refreshed the game and got a whole bunch right away. Makes it a little hard to judge the use of the limitation like this, though :/