To be fair, the game's graphics are pretty good - enviroments are well considered, although they have the occassional flickering texture map.
Lighting is good / very good, only criticism being poor volumetric effects at start - however, some nice sunset lighting mid game - which does make that stage look softer / more blurred overall (but controls sight lines)
Animation of characters could have been better; as Connor seems to do a very odd 'hip rotation' when controlling (always like he's dancing) - possible due to looking and moving synchronisation issues
Biggest flaw would be not sticking to the original Terminator concept that the Endoskeletons were extremely hard to take out, even continuing their hunt when cut in half - that would have been nice to include. Not seen film, so maybe that's deviated off that path too (presumeably because it would be almost impossible to defeat an army of them...)
'Friendly Fire' also impossible to achieve too - having accidental targetted the school bus, my shells appeared to have had no effect at all (not even any verbal abuse from the driver).
Cover system is nice though, with good animation sequences for Connor slidding / running between cover. But, like Gears of War, it does get a little tedious / formulaic - as do the 'flanking' moves - larger playable set areas would make it more interesting eg Ghost Recon style or Full Spectrum Warrior (allowing wider / more challenging flanking moves to occur).
Still entertaining though - which is the point.
Hopefully the games will mature more with the new movies. Better scripts / dialogue for characters too - female assistants in game have very lame dialogue (almost as if they are being plagued by mosquitos - rather than vicious robotic hunter killers...)