One Must Fall: 2097 [cheats]

Falling Scrap Metal
Press the keys REIN while fighting for scrap metal to fall from the top of the screen.

Advanced options:
Hold 2 + 0 + 9 + 7 at any point in the game. Enter the options menu to access increased height, vitality, damage, difficulty, and other selections.

Deadly difficulty level:
Press [Right] several times while "Champion Level" is displayed. The "Deadly Level" will appear. Note: This code may only be enabled in single player mode.

Ultimate level:
Press O + M + F to select the Ultimate level. Note: This code may only be enabled in single player mode.

Select robot color:
Press 1, 2, or 3 on the top row at the robot selection screen to change the first robot's color. Press 4, 5 and 6 to change the second robot's color.

Metal debris:
Press R + E + I + N while fighting an opponent. Pieces of metal will fall when your opponent is hit. For the same effect with different intensity, hold B + I + G and press a number on the top row.

Easy money:
Purchase a Shadow Robot. Max out the Armor, Stun Resistance, and Leg Speed, and minimize the Leg Strength. Fight your way to Raven in North Am tournament. (This may also work with other Bosses.) Continually advance and quick kick during the battle. The combo meter will fill, allowing the fight to end in a perfect match, with a large amount of bonus money.

Upgrade robot quickly:
If you want to upgrade quickly to another robot (Pyros, Shredder) when in tournament mode, win against everybody except Raven. Lose against him in your first attempt, then win in your next attempt. The game's offering of robots is not based just upon money and your robot.