Unlock everything:
     At  the  main  menu, hold L1 then press Right, Right, Left, Left,
Down, Up, Circle.

Unlock Bonus Characters:
     Beat  arcade  or  story  mode  using  the following characters to
unlock bonus characters:

Unlock:       Beat:
Bastion       Story mode w. Magneto (without losing)
Bishop        Arcade mode w. Gambit
Blob          Arcade mode w. Bishop
Dark          Phoenix Arcade mode w. Phoenix or Story mode w. Magneto
Psylocke      Arcade mode w. Betsy
Pyro          Arcade mode w. Dark Phoenix
Sentinel A    Arcade mode w. Cyclops
Sentinel B    20 wins in Survival mode