A hacker has cracked 1993 fighting game Mortal Kombat 2 to allow access to three CPU opponents as playable fighters, as detailed in a post on the Pugsy's Cheats forums.
The hack, discovered by forum users "Abystus," requires rewriting the game's code to allow characters Jade, Noob Saibot and Smoke to be selectable.
Normally, players get a chance to fight these three characters in Mortal Kombat 2 after certain in-game conditions are met. According to Abystus, the characters retain all special abilities as well as their speed, health, damage amounts and projectile invulnerability from their respective boss fights.
Fighting against the CPU with these characters will also ramp up the difficulty level. He notes that this version of the modifying code is not final and could be somewhat buggy in a few areas until he refines the method.
The steps to do this are detailed in the hacker's forum post — a somewhat more complicated measure than simply swapping out character sprites, which has been done in the past. Abystus' post also details the moves available for each fighter as well as work-in-progress moves.