I'm thinking of listening to "Crazy" from MadWorld when playing NetHack. Its first verse and its chorus fits NetHack quite well, in my opinion:
See the day turn into night.
See the blackness, where's the white?
Through the darkness there's the light.
Full moon, you're consumed, now you're terrified.
Hear the cries from the castle,
Cold stones ache and the moans start to grab you.
You can feel ‘em shake, you can feel ‘em bash you.
Bones start to break and your heart starts to craaaaaaaaaaaaash.
Will it be your last breath?
Will it be your last move?
Will it be your last step? (Step)
Don't step too close.
Or else it’s gonna make a mess when your chest explodes
Yea don't the full moon make you go Crazy? (crazy crazy crazy)
Caught up in a maze, dark and twisted,
Let's see who the craziest is!