Ready to rock - Clear the first level.
Stabilized - Get all medals in any level.
All powered up - Have all 4 power-ups at the same time.
Ambitiously ambidextrous - Clear at least levels with all 3 controller types.
Bubbler of the week - Get 10 enemies within the same bubble.
Skull and crushed bones - Crush 10 skulls without touching the ground.
Firewalker - Defeat 100 enemies using the Fire Boots.
Best Friends Forever - Revive another player 10 times in co-op.
Hard as Rock - Complete the game on Hard difficulty.
Given to wail - Clear all levels using a guitar.
Incognito - Clear each level collecting less than 20 points.
The Per Lundberg Syndrome - Get 100% of all medals.