Completion bonuses -
Successfully complete the game to unlock the hard difficulty setting
(enemies at level 50). You can also start a new game with your previous
characters at their current experience level.
Play as Xavier -
Successfully complete all Dr. missions to unlock Xavier.
Unlock Deadpool -
Beat the game.
Unlock Iron Man -
Collect homing four homing beacons per act, after four are collected get
a piece of Iron Man's armor, in Act 5 after locating beacons save Iron
Man.
Unlock Professor X -
Beat all the Danger Room mission.