Mortal Kombat 2 Cheat Codes for Arcade

Fight Smoke
To fight Smoke, press DOWN + START on the Bridge stage when Dan says "Toasty!"

Pong
Get 250 fights (the number of battles at versus screen) and a message will appear transporting you to another dimension. Both players can now play Pong, who ever wins continues to play.

Fight Jade
To fight Jade, work your way to the match before the mystery fight (the one titled "?"). During this battle, defeat your opponent using nothing but low kicks. If you manage this feat you'll fight Jade in the next battle.

Fight Noob Saibot
To fight Noob Saibot, get 50 wins in a row.