Enter these cheats in the Options/Cheats Menus.
Code                    Effect
MONROE                  Storm's swimsuit Card
SAVAGELAND              unlock all Fantastic Four comics
NZONE                   unlock all Tomorrow People comics
THEHAND                 unlock Electra swimsuit card
REIKO                   unlock Solara swimsuit card


Unlockables
Characters

Unlockable              How to Unlock
Play as Brigade         Successfully complete the Iron Man 3 mission in story mode.
Play as Daredevil       Successfully complete the Daredevil 3 mission in story mode.
Play as Fault Zone      Successfully complete the Storm 3 mission in story mode.
Play as Hazmat          Successfully complete the Magneto 3 mission in story mode.
Play as Iron Man        Successfully complete the Iron Man 3 mission in story mode.
Play as Magneto         Successfully complete the Magneto 3 mission in story mode.
Play as Paragon         Successfully complete the Paragon 3 mission in story mode.
Play as Solara          Successfully complete the Venom 3 mission in story mode.
Play as Storm           Successfully complete the Storm 3 mission in story mode.
Play as Van Roekel      Successfully complete the Paragon 4 mission in story mode.
Play as Venom           Successfully complete the Venom 3 mission in story mode.


Unlockables arenas

Unlockable              How to Unlock
Daily Bugle Rooftop     Be Spiderman and fight against Venom in the New York City bridge area on VS mode


Versus Mode Unlockables

There are certain bonuses that can be unlocked by playing versus matches.
Win the indicated number of versus match to unlock the corresponding bonus:

Unlockable              How to Unlock
Brigade                 120
Daily Bugle Venue       10
Dare Devil              20
Fault Zone              50
Grand Central Station Venue	30
Hazmat                  140
Human Torch             100
Iron Man                110
Magneto                 130
Niles Van Roekel        160
Paragon                 150
Power Plant Venue       60
Roekel's Headquarters Venue	90
Solara                  80
Storm                   40
Venom                   70