Complete the following achievements to unlock Xbox Live Gamerscore points.
Ready to rock (5 points): Clear the first level.
Stabilized (15 points): Get all medals in any level.
All powered up (15 points): Have all 4 power-ups at the same time.
The Per Lundberg syndrome (30 points): Get 100% of all medals.
Hard as Rock (25 points): Complete the game on Hard difficulty.
Ambitiously ambidextrous (15 points): Clear at least 3 levels with all 3 controller types.
Bubbler of the week (15 points): Get 10 enemies within the same bubble.
Skull and crushed bones (15 points): Crush 10 skulls without touching the ground.
Given to wail (20 points): Clear all levels using a guitar.
Firewalker (15 points): Defeat 100 enemies using the Fire Boots.
Incognito (25 points): In single player, clear each standard level collecting less than 20 points.
Additionally there is one secret achievement:
Best friends forever (5 points): Revive another player 10 times in co-op.