Street Fighter Anniversary Collection
Hold these buttons down when you are going into Sean's bonus stage:
Get Akuma in Hyper SFII:
Choose Super T Mode. Then hover your selection over Ryu for 1-5 seconds. Do this for T.Hawk, Guile, and Cammy in that order. Then highlight Ryu again and wait for 1-5 seconds again. Press START then immediately hit LP + MP + HP. If the portrait is a black shadow, the code worked.
Hidden Costume Color:
For any character, hit LP, HP, and MK.
Thanks to Revolution readers Evil_Ken and Carl!