The stories of past Grand Theft Auto games have been predictable and not very gripping (in my opinion), not so here because the tale of Niko Belic, the immigrant seeking revenge for the deaths of his friends and family is both interesting and exciting and seeing how it plays makes the game stronger on a whole.
As far the mechanics of the gameplay are concerned, the actual shooting works well, the game gives you the option to use auto aim (the default setting) or you can play the game without it. Playing without auto aim makes the game feel like gears of war or a standard third person shooter, I prefer turning auto aim off because sometimes you'll be in the middle of a firefight and accidentally target a civilian (if you have auto aim on), leading to some frustrating deaths.
The driving mechanics take some getting use to, mostly because the new physics engine (which makes the driving a lot more realistic) can be a pain, but once you do get the driving down, you'll like it.
OK, so the mechanics work well (for the most part) but what will you being doing with those mechanics, well, you'll being going on missions, a lot of missions, the missions range from stealing a bag of drugs from an abandoned hospital to chasing two bikers through a subway system. The missions have a lot more variety then past games, although maybe still not enough on a whole.
The tunes you'll here on the radio (while driving) vary from rock to reggae (theirs definitely something in here for everyone).
The cover system is bad, really bad, its hard to choose where you want to go into cover at and even when you do, trying to get out of cover can be a pain(considering taking cover is needed to survive, this is a big flaw). Overall the controls aren't that great, to run you have to tap the A button and getting Niko to stop moving on a dime can be tough. The controls sour the experience more then they probably should. Besides the prettier graphics and better story their isn't much innovation over previous installments in the series.
The Bottom Line
Even though there aren't many flaws the ones that are here hurt really hurt the game, their is a noticeable lack of polish to just about everything. The bad controls and cover system (turned) will turn a lot of people off to Grand Theft Auto 4. The lack of innovation is very frustrating (you still cannot go in many buildings), When you add everything up Grand Theft Auto 4 makes for a fantastic rental.