Unlockables
Colored Gems
- Red Gem: It is found on the level 'N. Sanity Peak', the second level of the N. Sanity Island dimension. Go through the stage as you'd normally do until you come to the second door that a ghost rat running on a wheel opens. Check the nearby wall to the right of the door to see a carving scratched into the stone. This is the path you'll need to take on the following platforms, which is to go in a counter-clockwise circle starting from the bottom left platform. Once you've gone all the way around, jump to the center and the red gem will appear at the top of the area.
- Green Gem: For our next gem, head over to Hit The Road in The Hazardous Wastes dimension. Make your way as normal nearly to the end of the level when the huge fire-breathing truck is chasing you. When you make it to the checkpoint, kick the trashcan on the left to knock out a weird remote control. Keep spin kicking the remote to move a little RC car into the nitro crate and explode into the green gem. Don't question why – just pick it up and finish off the stage.
- Blue Gem: Complete the level 'Off-Balance' without breaking any boxes. Note: enter the bonus round and then die immediately. From then on, the bonus round will act as a check point.
- Yellow Gem: On the level 'Run it Bayou', you can see the yellow gem right at the beginning of the stage. Before you get on the jet-board, platform your way over to the right across some crates and onto a moving platform. Go to the left before a series of mines in the water where there's a 2x2 stack of crates. Bounce off the top left crate and double jump in the air to pick up this last gem off-screen.
Skins
Skins can be unlcoked by collecting gems and inverted gems within a level. Colored Gems do not count towards the skins.