Here are some cheats and tips for the game Mortal Kombat Trilogy.
Play as Chameleon:
To play as the hidden fighter Chameleon, at the fighter select screen,
select Human Smoke. Then press and hold Left, L1, R2, [Square], and
[Triangle]. Keep these buttons held until the fight starts. When the
match starts, Human Smoke explodes into Chameleon. Chameleon has the
powers of Classic Sub-Zero, Rain, Smoke, Ermac, Scorpion, and Noob
Saibot.