Marvel vs. Capcom
Play as Onslaught:
Beat the game with Ryu without losing a round and you should get Onslaught. He appears under Wolverine.
Play as Shadow Lady:
Beat the game with Chun-li and you should get Shadow Lady. She appears under Gambit.
Play as Mega War Machine:
Beat the game with War Machine and you should get Mega War Machine. He appears Zangief.
Play as Orange Hulk:
Beat the game with Hulk and you should get Orange Hulk. He appears above Ryu.
Play as Roll:
Beat the game with Mega Man and you should get Roll. She appears beside Mega Man.
Play As Hyper Venom:
Beat the game with Venom and you should get Hyper Venom. He appears above Chun-Li.
Play as Lilith:
Beat the game with Morigan and you should get Lilith. He appears under war Machine.
Shadow as a Tag Partner:
After beating the game with Chun-Li or Shadow Lady, highlight Iceman and press down at the character selection screen.
Sentinel as Tag-Partner:
Beat the game as Onslaught, and Sentinel appears under Colossus in the Special Partner screen.
First select Spider-man or Venom as your character. During the match execute a web throw and throw your opponent at the right side 2 times. At the second time the wall will break away. There you will find E.Honda's old stage.
Thanks to Revolution readers MaN i'm StranG, Alexander Lips, Jereme Hiestand and Jason Allen!