Enter the 'Special' menu with any character when you have a saved game file from 'Ratchet And Clank: Size Matters' on your memory stick. Then select the 'Check Size Matters Save' option go to the 'Skins' menu to access new free skins.
Keykard #1:on asinanica where the cop cars pop up the second time and after you get on top of the first cop car look down on the left side and you will see the (RED) KEY
keykard #2:ok the second keykard is on for sprocket go to the gadge bot challenge to open the vault to save clank wen you get to the third troly don't go foward go backward and you will see the(BLUE) KEY
keykard #3:now the third key kard on quarks fourth chapter wen you rescued the second space nuns go to the third space nuns wen you get to the end where that alien is shooting at you there are space nuns behind him look at the center of the stage hoot at it while jumping towards the center you will fly and you will get the (YELLOW) KEY.
PS U NEED ALL ALIEN CODES TO MAKE THE KEYKARDS USEFUL
Unlock 'Ratchet & Clank: Size Matters' Ratchet SkinsAdded 23 Jun 2008, ID #2218
Using any character go to the 'Special' menu and select the 'Check Size Matters Save' option. If the game detects that you have a 'Ratchet & Clank: Size Matters' save file on your memory stick several free skins which won't cost you any Titanium Bolts will become unlocked and accessible at the 'Skins' menu.