Get a certain number of skill points to unlock each of the cheats.

Cheat	How to unlock
Big Head A.I.	20 Skill Points
Big Head Ratchet & Clank	5 Skill Points
Mirror Worlds	30 Skill Points
Secret Agent Clank	15 Skill Points
Ships to Ducks	25 Skill Points
Time Freeze	10 Skill Points
Wrench Replacement	Enter code from Demo