Complete the following tasks to unlock the corresponding hidden character.
On the 'Dungeons And Dickholes' level, find a door with a switch behind it. Use Couch Guy to reach the switch with his attack.
Unlock Couch Guy:
On the 'Future F*ckballs 2010' level, reach the red and blue disappearing platforms and continue right, through the lasers, and find him.
Unlock B.S. Man:
On the 'Beat It & Eat It' level, go as far to the right as possible. Instead of going down the ladder, switch to Mike to reveal a breakable wall.
Enter the following codes before the 'title' screen appears to enable the corresponding effect.
Unlock Hedgehog Mode (Run Fast)
Press Up, Down, Left, Right, A(Jump).
Unlock Big Head Mode:
Press A(Jump), B(Fire), A(Jump), Y, A(Jump), B(Fire), B(Fire).
Unlock Blue Screen Of Nerd:
Press Up, Up, Down, Down, Left, Right, Left, Right, B(fire), A(jump).