Whaaat?! You might as well said you didn't see the difference between all the MKs in the whole series. MK3 sucked, it didn't even have Scorpion in it, go figure. UMK3 added some secret characters arenas and such. And MKT was a mix of all the previous three MKs combined.

UMK3 was what MK3 was supposed to be, but they didn't have time to add everything they wanted, so they released the lesser MK3. UMK3 still wasn't complete when it was released(Missing Fatalities, etc). Finally Trilogy was released, with full list of Fatalities for everyone. Trilogy was also for fun. Probably to appease the fans of fantasy Vs. battles(Baraka Vs. Motaro for example). Trilogy features everyone from MK1-3 in an all-out battle for Earth, with both sides using all their forces.

I think of it this way, Kahn's invasion was split into 3 parts.

-The initial invasion of Earth when they were caught off guard, so few forces were needed for MK3. This is a prelude of what's to come.

-Kahn's higher-ups were brought in(Ermac,Jade,Reptile, Mileena), Kahn inadvertantly releasing Scorpion from Earth's hell, Kitana again aiding the Earth forces for UMK3. The battle for Earth is at a stalemate.

-Raiden finally decides to intervene, Baraka returns to aid Kahn, Cage appears from nowhere(retcon says he never died, so yeah...), Rain steps out of the umk3 shadows and becomes a full character. The final battle/climax of the MK3 invasion.



Ka-Tra

I have to sneak in with the obligatory "Scorpion doesn't make an MK game good" comment.

True,True.

MK3 is the base game.

UMK3 adds characters (the male and female Ninjas), adds moves (like Stryker's riot gun) changes properties of certain moves (roundhouses push out of corner, Sheeva's throw activates DP, Cyrax's air throw counts as part of a combo, Kabal's combos do less damage, etc) and changes general gameplay characteristics (added kick and punch air starters) and adds new backgrounds and menus.

MKT (for the PSX) adds more characters so that every MK character is represented, reproduces the gameplay of UMK3 with a few tweaks like Kung Lao's more balanced spin and certain characters doing MK2 level damage, adds moves for existing characters (Sindel's double fireball, double Kung Lao teleport, Scorpion's forward teleport) plus new menus and added backgrounds from MK1 and 2.

I say for the Playstation, because the N64 version does not accurately reproduce UMK3 style gameplay. They reproduce a broken hodge-podge of programming laziness, with bad graphics, and missing characters/