In the later planets, you can shoot the things flying in the sky.
Find them.
You have to do the skill points
By earning all the skill points, the more skill points you have the more cheats you unlock.
You need 20 skill points. there isn't a special code
Go to the Start menu, Extras, and Skill Points. You're actually able to check your skill points even in regular mode.
Snipe 10 Tyhrranoids in towers on planet Tyhrranosis. it's as simple as that
infect enimies with infector
Skill points let you activate certain easter-eggs and cheats in the game. You can access the skill point menu from the pause menu. The more skill points you get, the more stuff you can do.
skill points are used to unlock costume like turning in to a snow man and turning into a cragmite that's all i can remember :). also you can get a tresure map(which shows where the skill points are) when you defeat captain slag
Ratchet and clank, ratchet and clank going comando, ratchet and clank up your arsenal, ratchet: deadlocked, ratchet and clank size matters, ratchet and clank future: tools of destruction, secret aganf clank, ratchet and clank future: search for booty, and ratchet and clank future: a crack in time. I like ratchet: deadlocked the beSt
The more skill points you have, the more cheats you unlock.
Ratchet and Clank Ratchet and Clank 2 Going Commando or Locked and Loaded Ratchet and Clank 3 Up Your Arsenal Ratchet Gladiator or Deadlocked Ratchet and Clank Size Matters Secret Agent Clank Ratchet and Clank Future Tools of Destruction Ratchet and Clank Future Quest for Booty Ratchet and Clank Future A Crack In Time Ratchet and Clank All 4 One