Rockstar wanted to show us realism at it's best. They did it.
2. Optimization/Performance - 8/10. Too big system requirements. But the graphics are sooo brutal, so we can forgive Rockstar
3. Audio - 10/10 Typically for Grand theft Auto the sound acting is great and the soundtrack is perfect.
4. Gameplay - 9/10. You can use your phone to call friends and you can visit clubs, bars, strip clubs, you can play bowling, pool, darts, boating, cruise with helicopter and more. You can use internet in the game, get jobs from there or date new chicks. During some missions you can decide to kill somebody or save the bullet. Also the end of this game is up to you.
5. Story - 10/10. Very good story. You play as russian immigrant Nico Bellic. First he will help his cousin Roman with his small business, but soon he will mess with the mafia.
6. Artificial Intelligence - 10/10 - When you walk on the street you get the feel like the people you see are really alive. Their behavior is very realistic. Your enemies are even more intelligent than you are :-D. This make the game a bit hard sometimes
7. Physics - 10/10 - No comment here. Just one word: PERFECT.
8. Realism - 10/10 - Playing this game makes you forget that you are home on the PC. It really takes you in Liberty city and you really are Nico Bellic. :)))
9. Total - 10/10. Giving this game less than the max is a CRIME. There is only one minus. Many parts of San Andreas' gameplay are removed. You won't be able to fly with the Hydra, you cannot customize vehicles no more, you won't be able to go to the gym and make big muscles, or change Nico's haircut. If you are a big fan of San Andreas (like me) you will be a bit disappointed. But if you give GTA IV a chance, you will be playing it not for hours, but for days nonstop :)