Every character that has ever appeared in a Mortal Kombat game prior to Mortal Kombat Trilogy appears in this game. Rain and Noob Saibot are playable for the first time with their very own moves, combos, and finishing moves. Along with the Ultimate Mortal Kombat 3 roster, Mortal Kombat Trilogy adds Baraka, Johnny Cage, Raiden, and “klassic” versions of Raiden, Kano, Jax, and Kung Lao, and Bosses Goro, Kintaro, Shao Kahn, and Motaro are also now playable.
A new secret character appears, as well. This character known as Chameleon appears, and rapidly switches between all the male ninjas (Classic Sub-Zero, Scorpion, Reptile, Ermac, Rain, Human Smoke and Noob Saibot). In order to play as him, you have to perform a special button combination before the battle starts. Basically, Chameleon is a newer version of MK1 Reptile, but Chameleon randomly changes his color, not just his stance.
He also revealed that the game is not related to the Mortal Kombat vs DC Universe game, and that they were again aiming for a “Mature” rating, contrarily to the “Teen” rating attained by the previous game.
The Nintendo 64 version, due to limitations of cartridge space, lacks the classic versions of Raiden, Kano, Jax, and Kung Lao, and as well as Goro and Kintaro. Also, Shao Kahn and Motaro are not selectable at the main screen.
Cheat codes have to be entered to gain access to them. The N64 version also combines the two Sub-Zeros into one convenient palette swapped version. Chameleon is replaced in the N64 version with the secret character Khameleon, a grey female ninja, and is present as both a secret opponent and a playable character. While she too switches her move sets (making her considerably weaker), she does have a cohesive storyline, unlike her male counterpart.