Unlockable: Bonus Ending
Complete the game and wait through the credits.
Unlockable: Mini Games
Murrayball: Go to the Palace of Prostheses and look up the name Ryan J. Danzwithwolves in the files. (You must do this before looking for the No-Nosed Man). Murrayball will show up in Bonus Stuff. Note: Do this before looking for the no-nosed man.
Monkey Invaders: Complete the Monkey Kombat table for every stance. View it by pressing R2 in Monkey Kombat.