Mortal Kombat 2

Test mode:
Enter the options menu and highlight the "Done" selection. Press Left, Down, Left, Right, Down, Right, Left(2), Right(2). A "Test Mode" option will appear to confirm correct code entry.

Fight against Jade:
Defeat the opponent in the match before the question mark only using the D-pad and LK. Jade will be the next opponent.

Fight against Noob:
Win 25 consecutive matches. The phrase "Incredible winning streak! A new warrior awaits you." will appear. Noob will be the next opponent.

Fight against Smoke:
Execute upper cuts on the Red Portal stage until Dan Forden appears. Quickly press Down + Start to fight Smoke.

Fight against Shao Kahn:
Press A, B, C(3), B(2), A(4) at the options menu. Quickly press B when Shao Kahn appears to fight in the final stage.

Pong Kombat:
Defeat player two in 250 consecutive matches.

Fergality:
Enable the "Test mode" code and set the background to "6" and enable the "Ooh Nasty" option. Select Rayden as your character. Win the match by pressing Away(3), Block.