Even with a few minor flaws, GTA4 still outnumbers in the positive department and remains truly fantastic. (deep review)
The graphics, technically, are good, and are incredible artistically. There are wonderfully designed ghetto neighborhoods and lavish ones. You'll notice plenty of nice shadows, but at times the game may get TOO dark. Whether its trying to find your way through an unlit alleyway at night or even under a thick shadow in the middle of the day, it may get pitch black.
The most significant change from previous GTA games is that pretty much everything is accessed through Niko's cellphone. You can phone characters(to inform them of your current situation, to organize activities(we'll get to that later), and to get missions from them), take pictures, use cheats, and receive text messages through it.
Driving vehicles is great, because each vehicle has a substantially distinct handling. They all look great, but the best part is the damage cars take. They get paint scratches for scraping, dents(or even extremely large indentations) for collisions, and different car parts can catch fire. If you drive through a fire, your tires might catch fire, and eventually pop after burning for long. They can also pop if you drift and burn rubber too much. What was an extremely welcome detail is that flipping your car doesn't result in explosions this time around.
The story and dramatic elements are certainly the best yet in the series. There were numerous points in the story in which I actually stopped, panicked a bit, and was actually experiencing denial when a character died. One minor character gets ran over by a car, resulting in their death. I stopped, though "no! no way!", called an ambulance (in the game), and watched his body. The situation would've maintained its emotion if the paramedics weren't idiots and only cared about Niko and just left the dead body there.
Throughout the game you will have to choose whether or not to kill a character. The illusion of free will (that was a reference to Half-Life) is present, because choosing NOT to kill them NEVER has negative consequences, and the character may appear later in the game to give you a mission. So there really is no point in killing any of them. There are actually two different endings you can get in the game, but they aren't really good or bad endings, which is good. That way you can't really get angry because you got the bad ending, because there is no bad ending.
During the game you'll encounter recurring characters, and some of them will become your friend. Through your cellphone you can arrange activities to do with them. Some of the activities include bowling, pool, darts, visiting the strip club, going on boat or helicopter rides, and even going to a bar to get drunk. Getting drunk is great fun, because you and you're companion will stumble all over the place and even fall if provoked. You can hail a cab, or do the irresponsible(AKA fun) thing and drive drunk. You're vision is blurry and its far more difficult to control the car in the manner you wish. And be prepared to escape the cops if they spot you.
During you're free time you can head pack to your apartment and watch some TV. There are various shows such as 'I'm Rich', 'Republican Space Rangers', and 'The Serrated Edge'. They are all pretty funny, but there are only one or two episodes of each show to watch. The commercials are also funny, my favorite being the Piswasser Beer commercial. It's basically a hardcore rock advertisement video with hilarious tongue-in-cheek lyrics. Such as:
"Piswasser, this is beer!/Drive drunk off a pier!"
The most exciting addition is the ability to play multiplayer online. Too bad it isn't much fun! Often you will have to wait for at least 20 minutes for people to play with, and the only game type that you can always count on is racing. And the racing is great fun. All of the modes are pretty fun, but aren't really worth waiting for so long. I always think about how much better the game would be if the online wasn't flawed.
Every pedestrian and character is part of the new Euphoria engine, which accurately and realistically mimics body and muscle movement. If you're standing facing to the side on a staircase the leg on the higher step will be bent up. And if you stand with one foot on the sidewalk and one of the street the leg on the curb will also be bent up realistically. Hitting pedestrians with cars is very fun, becuase they fly all over really realistically. You do too. If you're drunk and fall down a staircase, it's fun. Jumping out of a helicopter is fun. Pretty much everything that takes advantage of the Euphoria engine is fun.
What disappointed me was the fact that there is no sort of replay viewer/editor. San Andreas had a half-assed replay viewer, but at least it was something.
Personally, I think that San Andreas was better for its time than GTA4 is now. An incredible game would be San Andreas remade with the GTA4 engine.
Even though Grand Theft Auto 4 has a few flaws, it still maintains a state of awesome throughout the whole experience. It is definitely worth purchasing and among the greatest games of all time (just behind San Andreas).