By Maria Montoro
As you advance through the game, your character will have access to other vehicles like boats and planes. There are different kinds of boats, and they allow you to run away from certain areas and complete certain missions. They were more prevalent in Vice City, as it was inspired in the Miami way of life.
The weapons haven't evolved much throughout the series, although there have been some differences. The artillery found in Vice City was retro: old hand guns, machine guns, sniper rifles, rocket launchers, etc. In San Andreas they had current models like MAC10, Uzis, etc. The higher up you go in ranks, the better weapons you get. You'll always need the right weapons for the right jobs, and you'll also learn where to get them.
You couldn't drive motorcycles until Vice City. San Andreas and GTA IV added them to the formula as well. Motorcycles are really fun to drive, as they allow you to perform wheelies and stunts, as long as you have the right one. There are choppers, scooters, and dirt and street bikes. They all handle differently, and you get rewarded for your performance with bonus points.
The police are the most noticeable and relevant A.I. of the game. They were pretty stupid in Vice City and GTA 3, but in San Andreas they evolved into a more strategic kind of NPC. They started working in teams and had a more sophisticated tracking system. However, it was still easy enough to get away from them. GTA IV represents a big step up in this department, with much a smarter A.I. and a more complex tracking system. In other words, it's tougher to get away!
Overall, the most significant evolution of the series other than the graphics is found in the gameplay style. The old GTAs used to be more arcade-ish and mission-based, whereas today's GTA is more like a sim; it offers more side missions and gives you extra freedom to go to places and do different activities, like eating, going to the gym, bowling, playing pool or even going to a night show. The social aspect is more prevalent in GTA IV, and your physical health is much more important this time around.