Murrayball mini-game:
Go to the Palace Of Prostheses and use the filing system. Enter "Monkey-Pumpkin-Bunny" as a code.  You get the Ryan J. Danzwithwolves file. Look at this file, pause the game and then select the "Bonus Stuff" option to access Murrayball.


Monkey Invaders mini-game:
Complete all Monkey Kombat moves in the moves table successfully and press R2 for each Move.


See Monkey Kombat moves:
During Monkey Kombat hold R2.