To gain the following items listed, you'll need a number required items in your possession:

Fire-Bomb:
Mega bomb helmet, torso, boots, Wild fire gloves

Ice II:
Crystallix helmet, Hyperborean torso, gloves, boots

Shock Crystal:
Electoshock helmet, boots, Crystalix torso, gloves

Stalker:
Wild fire helmet, Chameleon torso, boots, Sludge Mk 9 gloves

Triple Wave:
Wildfire helmet, Electroshock torso boots, Sludge Mk 9 gloves

Wildburst:
Sludge Mk. 9 helmet Wildfire torso, gloves, boots

To get the following skins, perform the tasks. You can turn them on and off in the Specials menu:

Dan Skin:
Be the winner of 5 matches of Iron Lombax, Deathmatch and CTF each (that's 15 matches in total).

Plundering Pirate Captain Skin
Get 6 Titanium Bolts

Ratchetzilla Skin
Get 6 Titanium Bolts

Troical Vacation Skin
Get 4 Titanium Bolts

Below, achieve the listed amount of skill points in order to unlock the cheat. You can turn the cheats on and off anytime you wish from the cheats menu.

Big Headed Clank - 03
Big Headed Enemies - 14
Big Headed Giant Clank - 01
Big Headed Ratchet - 05
Bolt Confusion - 20
Climb The Treehouse - 25
Hardcore Mode - 24
Mirrored Levels - 10
Mooo! - 24
More Cowbell - 08
Old Timey - 24
She's On Fire! - 07
Super Bloom - 12
Weapon Switching - 16