>but it changes significant aspects of the game's plot
This is always going to happen, you can't fit a good plot into an hour and a half movie. That being said it was still about a tournament to protect earth from outworld, it was high energy and used relatively unknown actors for the roles (which video game movies should ALWAYS do).
Mortal Kombat (the first one) will always be the best because the 'plot' of the game (and the characters) is so simplistic making it almost impossible to fuck up. You go in expecting cool fights and fun one liners and that's exactly what you get.
Anything more complicated than 'earthlings fight warriors from other realms to keep earth from falling under their control' will ALWAYS get fucked up. Sure we might get the occasional fun movie like Resident Evil: Apocalypse that gave us Jill and S.T.A.R.S but generally if you like that movie (I do) it's because you didn't really care for RE games and don't care about the non-game add in stuff like Alice.