Alternate costume:
To turn Spider-Man’s costume into Venom’s black costume, while waiting for any of Spider-Man’s missions to load, hold Select.
Play as Carnage:
To unlock Carnage in Multiplayer mode, get a 80% game completion.
Play as Symbiote Spider-Man (black costume):
To unlock Symbiote Spider-Man (black costume) in Multiplayer mode, get a 100% game completion.
Stop Venom’s death:
While playing as Venom and he is dying, drag the stylus from him to the ceiling. He will resurrect and you still be able to play, but with an empty life bar.
Defeating Electro:
When you fight Electro, about half way through the game, hit him with your tendril. When he turns blue, use the stylus to throw blue mail boxes and the car. Note: The car will respawn if you destroy it. If he gains health, use the tendril when he is red to take out the street lights. Note: The lights will flicker after you hit them, but if they are not out he can use them to regain health.