A very good game indeed, but several small things keep it from the perfect game most people think it is.
Gameplay- First, I have to give major props to the story. The Balkan Niko you play as is an excellent character and you really feel like him, his cousin, and most of his friends don't deserve this horrible lifestyle. You can really get into these characters and feel their story. The gameplay is just as strong as the story. It's most of what you would expect from a GTA game, with a few more bonuses. There are basically more of everything. More people, more cars, more entertaining radio stations and much much more. The attention to detail is outstanding, and there is a lot to keep you busy. You advance through the single player by unlocking friends and different parts of the city. You come to like and hate the characters you meet and the plot takes some very interesting turns. You can even make choices to decide the outcome of the final ending. The shooting mechanics work, though it was an odd decision to have the auto lock and the free aim on the same button in my opinion. Everything is very well done in the gameplay done. The one problem I have with the gameplay is that there are less weapons and your character feels a bit sluggish sometimes. The multiplayer is very well done as well with lots of different modes to play and most of the singleplayer experience is in tact here. The one complaint is that i've lost connection a lot with other players and you have to go back to the single player if that happens.
Graphics- This is the first thing that's really sets the game apart from a perfect 10. Regardless if the game is huge or not, the graphics just aren't up to standards these days. It's a good leap from past games but not quite big enough. Facial expressions are strong, but there are lots of glitches, and overall, the textures and pixels just aren't there.
Sound-The best part of the game, like the the other GTA games in my opinion is the sound. The radio stations are SOOO funny and varied, and the voice acting is incredibly well done. Music is great as well, in all the stations.
Value- With a really long single player, lots of bonus things to do and find, a nice multiplayer, and alternate endings, you should buy this immediately if you can. This is one of the best values you can get right now.
Grand Theft Auto 4 is an amazing game and I'm so glad I spent every penny. It is very well done, however it does not deserve a perfect score. There are too many small issues for that to happen. Buy it!