Key of Lunacy is awarded at hub after completing all levels.
Holy [NOUN]! (Rocket Keychain)[]
Just use the machine gun and make all the way to the end.
For the Rocket Keychain,before you enter the bone pit, check for a hidden passage to the right in the darkness and follow the signs to it.
Then go into the bone pit and beat the thiefing crab and grab the key to end the level.
Asylum in the Forest (Hammer Keychain)[]
Chase the mad man into the asylum, then mash any enemies and make your way through the asylum.
Otherwise a pretty standard level. Just note for the Hammer Keychain, check the left wall at the grass machete section for it,it's in a hidden lava passage there.
A Monkey Auction? (Squash Keychain)[]
Push the Sea Cucumber into the forest to hide it for the Squash Keychain.
Make your way through the forest, watch out for the lake section while chasing the dog down. Then once past the lake, enter the shed,grab the weapons, then go and smash the dog and it will warp you back to your house, which you can end the level.
Brains 'n' Madlibs (Pumpkin Keychain)[]
Pumpkin Keychain is at the bottom right of the level behind a tree.
Otherwise,look around for firepower,bump into items and mash Dr L to end the level.