Pause the game to display the "Fortress Of Solitude" menu. Then, enter one of the following codes at this menu to activate the corresponding cheat function. If you entered the code correctly, you will hear a sound. Note: Some codes cannot be enabled until the Warworld level (level 3) has been completed.
Play as Bizarro in Free Roam mode - Pause the game and press Up, Right, Down, Right, Up, Left, Down, Right, Up. Then, fly to the marker at the top of the GNN building to change to Bizarro. To change back to Superman, go to the marker at the other end of Metropolis.
Infinite city health - Pause the game and press Circle, Right, Circle, Right, Up, Left, Right, Circle.
All power-ups - Pause the game and press Left, Circle, Right, Circle, Down, Circle, Up, Down, Circle(3).
All bonuses - Pause the game and press Left, Up, Right, Down, Circle(3), Up, Right, Circle to unlock all bonuses.
Alternate costumes - Successfully complete the indicated task to unlock the corresponding costume:
Golden Age suit: Save Metropolis from the tornadoes
Pod suit: Defeat Bizarro
Trophies - Successfully complete the indicated task to unlock the corresponding trophy:
Bizzaro Unchampion: Successfully complete all Bizzaro mini-games
Globe Bowling: Pick up the Daily Planet globe
Kitten Finder Extraordinaire: Rescue all 100 kittens
Meteor Mayhem: Successfully complete Level 1
Outstanding Valet: Pick up 500 cars
Photo Finish: Defeat 500 opponents
Breaking the sound barrier - While flying as Superman at hyper speed, he goes through stages where after an amount of time of continuous flying he gains a burst in speed. He accelerates and becomes faster and faster. If you fly for long enough (flying a lap or two around the entire city above the sea is recommended), he eventually breaks the sound barrier. It is about the fourth jump in speed. You will know this has happened when the sound of him ripping through the air is suddenly silent. This is because Superman is traveling faster than his own sound.
Developer memorial - In Research Park, by the Superman statue, there is a memorial to Derek Allman, one of the developers. The game is dedicated to the memory of him as said in the credits.
