Skill Point Cheats
Throughout the game, you'll collect a varying number of skill points for completing various tasks. To unlock certain cheats, simply collect the corresponding number of skill points. To unlock "Big Headed Giant Clank" mode, collect one skill point. To unlock "Big Headed Clank" mode (where Clank has a big head even when not a giant), collect three skill points. To unlock "Big Headed Ratchet" mode, collect five skill points. To unlock "She's on Fire!" mode, which lets you set your enemies aflame, collect seven skill points. To unlock "More Cowbell" mode, which creates a cowbell sound when you hit an enemy, collect eight skill points. To unlock "Mirrored Levels" mode, which flips the orientation of the levels, collect ten skill points. To unlock "Big Headed Enemies" mode, which gives your enemies big heads, making them easier targets, collect 14 skill points. Finally, to unlock "Hardcore Mode," which is an extremely tough difficulty setting, collect 24 skill points.
Hidden Skins
These skins, which can be accessed via the "Specials" menu when you pause the game, basically give your players a new costume. You can unlock them by collecting titanium bolts, which can be found scattered throughout the game world. To unlock the Tropical Vacation skin, collect four titanium bolts. Collect six titanium bolts to unlock the Pirate skin and Ratchetzilla skin. To unlock the Dark skin, you must play ten online battle matches, not necessarily in a row, without dying.
Secret Weapons
There are four secret weapons you can access throughout the game by combining different types of armor. Acquire the Flaming Wrench simply by wearing all of the available Wildfire armor. The Freeze Wrench is accessed similarly, but you must instead wear the full set of Hyperborean armor. You can acquire another weapon, the Triple Wave, by wearing a Wildfire helmet, Electroshock torso armor and boots, and Sludge MK9 gloves. To unlock the Wildburst, wear the Sludge MK9 helmet with Wildfire torso armor, boots and gloves.