Best Terminator Game so far, but thats not really saying much...
While Salvation isn't anywhere NEAR terrible, it's not that great either. The game play is very fun and makes you feel desperate at times against the hordes of machines that never seem to quit, which can connect you to the struggle in the films. There are also so ok on rails sequences, which can get difficult at times. The music is awesome (it's Terminator music, duh?) and really matches the mood of the game. This game also have very easy trophy/achievement points (which may be good or bad for each person). You can get the Platinum Trophy in one play through on the Hard difficulty, which isn't very hard.
While it has some very good parts to it, it also has many bad or ok parts. The first and most noticeable of these is the graphics and character models. The graphics are ok, but feel unfinished and the character models are ok also, but can look extremely bad at the right angel. Christian Bale's voice and looks are also not present. And to be painfully honest, the voice actor for John Connor SUCKS. The game is also said to be very short. While I have not beat the game yet, I played for two and a half hours and completed about half of the game (on hard). Wow... short much? To match this, the game is also very easy. I'm playing on Hard my first time through and still it is not very difficult. And from what I can tell, there doesn't seem to be any reason at all to replay the game, except if you want to play with a friend on co-op. I have not tried the co-op yet for myself, but I plan to soon.
Over all, Terminator Salvation seems to be a very fun game, but it still has it's problems. The movie looks AWESOME (I'm going to a midnight movie of it :-) ) and the game complements it pretty well for a movie-based game. As a movie-based game, this is about as good as they welll get, but as a game over all, it's ok. I, myself, would recommend a rental, at least, due to the easy trophies and the fun of playing it just once.
Final Score: 8.0/10