X-Men: Children of the Atom 
Saturn

Play as Akuma (Works Best in Vs. Mode):


For Player 1:

 


Place you selector on "Spiral", then move it to the following characters in order: Silver Samurai, Psylocke, Colossus, Iceman, Colossus, Cyclops, Wolverine, Omega Red, Silver Samurai.  Then wait 1 second and press Weak Kick, Fierce Punch, & Fierce Kick at the same time.  




For Player 2:




Place your selector on Storm, then move it to the following characters in order: Cyclops, Colossus, Iceman, Sentinel (press left to get to him), Omega Red, Wolverine, Psylocke, Silver Samurai, Spiral.  Then wait 1 second and press Weak Kick + Fierce Punch + Fierce Kick.




After doing this code once, hold L+R+X+Y+Z and press start on the continue screen and Akuma's name will
 appear on the list. Cool topknot, eh?




Play as Juggernaut
:



In 2 player VS mode, use the code to activate as Akuma. Then die and continue.  At the character select screen tap Up Left(together) twice.  Juggernaut should show up on the second tap.  (Works for both Player 1 & 2)
 



Make Gouki Appear:


After putting in the Akuma code, after a match in vs. mode hold down the Left and
Right Shifts and press start at the stats screen. The name Gouki will appear at the bottom of the screen. 


Storm's extra hyper-X, Psylocks Taunt, Beat up opponents
:


Set the L & R buttons to do nothing.  It will now act like the start button in the arcade.



Do a quarter circle from down to front and press L.  Storm will do her Ice Storm mutant power.



Play as Psylock.  Press L to taunt opponent.



Press L between rounds to add some extra beating on your downed opponent.



Screen Size Option:


Go to the option screen and press Up, Down 5 times and new option called screen size
should appear!






Thanks to Revolution reader Guillermo Zapata!