here is my opinion about GTA 4:
GRAPHICS: are pretty good but not like mgs4 or RE 5. my score for graphics is 8.5/10.
STORY: only thing that i can say about story is woooow.... great story one of the best these days. my score 9.5/10
GAMEPLAY: is same as previous gtas with few improvements like u r able to crouch, take cover and now u have a mobile phone. my score 9/10
CONTROLS: they'll require some getting used to but anyone who says it's easier to play it with keyboard and mouse is wrong. score 10/10
LASTING APPEAL: after completing story there's a lot of extras like chasing bad guys in liberty city, stealing cars, getting all the trophies and many more. score 10/10
OVERALL: GTA 4 is outstanding game that'll keep u coming for more and more... it has great multyplayer and it almost can't be boring.
i recommend it. buy it.