An Awesome Game
You offered every character, even the 4 bosses, and all their moves and sounds are updated, their sounds are from the MK3 engine, and the text and speech as well. A few bugs occur here and there, and some long load times, but it's a fun reprisal of the series. However, for sound, some scores are a bit misplaced on the MKII levels, and the sounds of the MK3 music scores are in a different pitch of audio (people with absolute pitch will notice this). Not that it's bad. It looses some of the feel of the earlier games (for istance, on the arena level in MKI, Shao Kahn is in the throne and not Shang Tsung), and some levels from MKI don't show up. They are redone with scores from MK3, but it is still fun.
I see that they had to redo Johnny Cage, but they kept Baraka and Raiden for what they were like in MKII, you can also play as the MKII variants of Kung Lao and Jax, and the MKI variants of Raiden and Kano.
What is really unique about Mortal Kombat Trilogy is how all the non-MK3 characters that were from MKI and MKII have the run moves, and the devastating combos, in fact, you can pull of a 42% damage combo with Raiden. Rain and Noob Saibot are also playable with new moves (unlike their moves in the home ports of UMK3). I also noticed that in all the earlier MK games, when Johnny Cage won, it would just say "Cage Wins" and his health bar just says "Cage", but in Trilogy, it's his full name. This also applies to Noob Saibot as well.
More fatalities were added, although they removed Scorpion's fatality where he brings the opponent to hell and makes the other Scorpions mob him/her. They also added some new animalities, like Ermac's vicious frog animality, and Noob Saibot and Rain were given animalities as well. There are also the brutalites which were from UMK3 (supposedly). The Bablities and the Friendships are also there too. However, Sub-Zero (the masked version) lacks an animality. And of course, the secret character Chameleon. As for options, there is plenty of things you can alter. The secret box gives you good cheats like 1-button fatalities instead of performing painstaking combos to do them. There are also some cheats buried around the game as well,and the kombat kodes are there as well.
It has a lot offer, with great multiplayer and action. It's like playing all the first few games all at once. If you can overcome the minor bugs, it'll be a fun game you'll still be playing for years.