Fight as Akuma:
Select 2 Player Vs. mode.

For player one, highlight Spiral, then move to Silver Samuri, Psylocke, Colossus, Iceman, Colossus, Cyclops, Wolverine, Omega Red, Silver Samuri. Wait one second, then press the Weak Kick + Fierce Punch + Fierce Kick.
For player two, highlight Storm, then move to Cyclops, Colossus, Iceman, Sentinel, go left to get to Omega Red, Wolverine, Psylocke, Silver Samurai, Spiral. Wait one second and press Weak Kick + Fierce Punch + Fierce Kick.

Finally, hold L + R + X + Y + Z and press Start at the continue screen. Alternatively, select versus mode and use the "Quick continue" code to select Akuma.

Fight as Gouki:
Enable the "Fight as Akuma" code. Hold L + R and press Start at the stats screen. The name "Gouki" will appear at the bottom of the screen.

Fight against Gouki (Akuma) as the "Alpha" Boss:
The Game must be on "manual". Fight with no continues. Defeat your opponents two rounds in a row (do not lose a round), having "first attack" on each round. You must use "Hyper-X" six times or more and it must connect to the opponent each time. No missed or blocked "Hyper-X" nor blocked or "cheesy" one-hit "super finish" will be accepted. You must get a maximum number of combos hits from your character's Hyper-X at least once. If done correctly, Akuma will appear as the sixth opponent, before Juggernaut. His stage is the "Danger Room" and he fights like he does in Super Street Fighter 2 Turbo.

Fight as Juggernaut (North American version):
Select Vs. mode and enable the "Fight as Akuma" code. Fight and finish the match, but do not use the "Quick continue" code. Immediately press Up/Left(2) at the character selection screen. Juggernaut's face will appear to confirm correct code entry.

Fight as Juggernaut (Japanese version):
Select Vs. mode and enable the "Fight as Akuma" code. Fight and finish the match, but do not use the "Quick continue" code. Immediately press Up/Right(2) at the character selection screen. Juggernaut's face will appear to confirm correct code entry.

Quick continue:
Hold L + R when continuing to keep the same characters.

Quick select:
Hold L + R in 2 Player Vs. mode to avoid choosing the game options again.

Marvel Super Heroes screen:
Press Start + A + C on the controller two.

Beat up a defeated opponent:
After you have defeated your opponent, press Start to move and continue fighting.

Hidden options:
Pause a fight and press A or C. A menu that allows controller and sound options to be adjusted will appear.

Screen size:
Hold L + R, and press [Up, Down] six times on controller one at the options screen to choose between the Saturn and Arcade (wider) screen sizes.