To play as Assault, press Right, Up, Up, Right, Down, Right, Up, Up at the character select screen.
Play As Mayhem
To play as Mayhem, press Left, Right, Down, Left, Up, Left, Down, Left, Down at the character selection screen.
Play As Vitriol
To play as Vitriol, press Right, Right, Right, Up, Up, Down, Left, Left, Down, Down at the character select screen.
Supervisor
At the character select screen enter this code: down,right,down,up,right,down,left,down,up,right,up. the SUPERVISOR will appear in the bonus box if done correctly.
Play As Assault...