Grand Theft Auto IV is a brand new adventure in the GTA universe following the experiences of Nikolai "Niko" Bellic, a new immigrant from an undisclosed eastern European country whose troubled past and the persuasion of his cousin Roman have brought him to the fictional Liberty City. Unfortunately, Niko’s search for the American Dream and a much needed fresh start, hits an immediate snag when the rags to riches story Roman spun to pique Niko's interest is exposed as not only a complete fabrication, but a ploy to enlist Niko’s well-known skills as a tough guy against the ample list of enemies clamouring for Roman’s debt-ridden blood.
Because Roman is the only person Niko knows in Liberty City he begrudgingly accepts his role as Roman’s protector despite the deception. But as time goes on Niko comes into his own, and his experience on the wrong side of the tracks proves more valuable than he could have ever imagined as he fights for survival and later supremacy on the crime ridden streets of Liberty City in Grand Theft Auto IV.
Improved combat system - Now you can use cover and also a target lock system, which allows you to take out targets with greater ease and accuracy. Plus, you can engage in some hand-to-hand combat if you can't get your hands on a piece quick enough.
Free time - In between missions you can take advantage of "me" time. There are gentleman's clubs, comedy clubs, bowling alleys, and bars, which all house unique activities.
Take a break from the storyline - A variety of side missions allow you to help run a car service, "borrow" cop cars, assassinate targets, help solve problems for those on the street, or take to the air with stunt jumps that are scattered all over the city.
Control your own fate - Throughout the game choice moments will arrive causing you to make a decision that will affect relationships and money.