While standing in the Helicarrier, in between missions use the d-pad to enter the following codes.
|Left, Left, Right, Up, Down, Down||Unlock Venom|
|Up, Up, Down, Down, Left, Right||5000 Tokens (can only use once)|
|Left, Down, Right, Right, Down, Left||Unlock New Goblin|
|Right, Right, Right, Up, Down, Left||Unlock Sandman|
Thanks to Revolution Reader Yellowskinz!