The games soundtrack is synced up to the Platcore AI, so when the soundtrack goes boom, something else is going boom, and it's likely to hit you in the face.
If you chose the wrong control scheme, just reload the game and you'll be able to pick it again! :)
Be warned, if you skip through the tutorial - you can't get it back without deleting your save file! So read!
If you're experiencing lag - right click and turn the quality down! This is important as a few people experience lag for a reason unknown to me!