Use the following codes at hte indicated screen:
All characters: (main menu or a S.H.I.E.L.D. save zone menu) Up(2), Down(2), Left(3), Plus
All powers: (main menu or a S.H.I.E.L.D. save zone menu) Left, Right, Left, Right, Up, Down, Up, Down, Left, Right, Plus
All costumes: (main menu or a S.H.I.E.L.D. save zone menu) Up, Down, Up, Down, Left, Right, Left, Right, Up, Down, Plus
All cinematics: (Review menu) Up, Left(2), Up, Right(2), Up, Plus
All comic book covers: (Review menu) Left, Right(2), Left, Up(2), Right, Plus
All concept art: (Review menu) Down(3), Right(2), Left, Down, Plus
All wallpapers: (Review menu) Up, Down, Right, Left, Up(2), Down, Plus
Invincibility: (during the game) Up, Down, Up, Down, Up, Left, Down, Right, Plus
Level 99 team: (team menu) Up, Left, Up, Left, Down, Right, Down, Right, Plus
100,000 Gold Coins: (team menu) Up(3), Left, Right, Left, Plus
Super Speed: (during the game) Up, Left, Up, Right, Down, Right, Plus