Update: I was unfortunately not aware of Shamus Young's severe criticism of Fallout 3 available here to link in the original piece and I regret that. It dovetails rather nicely with what I've written and it's much better executed than my piece. I strongly recommend anyone...
In Freelancer, you are Eddison Trent, a freelancer (hence the title) who's just had his ship, and a lot of his money, blown up on an attack on the spacestation Freeport 7. You arrive on Planet Manhattan on the rescue ship, trying to think of what to do next.
Sound familiar? Every GTA, since GTAIII has started similarily: lone man in a new area with little money and no ride. How Freelancer and GTA differ is how it goes from there.
Unlike GTA, Freelancer has no car-jacking. This is not only due to the fact people use spaceships, not Tahomas to get places, but the ship you use adds to your total worth. Every ship you fly is yours to own. At least no-one can steal your ship.
What they can do is blow it to kingdom come, however. This is no pansy-wansy pacifist game. This is brutal space combat at it's best. You not only buy ships, but you buy guns for them, like you could do in GTA2. These ones are a lot better though. These guns aren't your ordinary machine guns or bazookas, this is space we're talking about. Laser cannons, torpedo launchers and other devices that pack more destructive power than the Enterprise are the way to go.
But they'll have to wait, as the first ship you get can't handle them. The first ship you fly is a gift from the LSF, the 'space police' of the Liberty systems in Sirius. Lost? Liberty is the name for the area of space which was colonised by the Liberty, a colonisation ship from the USA. Still lost? Too bad. As you venture into the story, you see the Rheinland, Bretonia and Kusari sectors.
What's really cool is how each sector has it's own ship designs. The Liberty ships are the standard sci-fi ship clones, while the Kusari ships have a noticable Asian flare to them. They carry fans for freaking out loud. Some of the rebel factions have even developed their own ships.
There are two classes of ship: Fighter and Freighter. The fighters get more guns and are easier to maneuver, but can carry less cargo. The freighters get more turrets and more cargo space, but are harder to steer. There are also Light and Heavy versions of each. Heavy fighters can carry more guns, more powerful guns and more 'special' weapons, like torpedos. The downside is that Heavy Fighters are more expensive, are rarer and you need to be really buddy-buddy with their maker. There are Heavy Freighters, and they carry more cargo , as well as all the benefits and downfalls Heavy Fighters get over the Light ones. There are also Very Heavy Fighters, but they are ultra-rare. Plus, only the evil guys get them.
Not everything can be bought however, and not everything needs to be bought. Your level depends on your total worth. This worth is calculated using your ship's worth, the worth of all your equipment and your free cash. You raise this total any freaking way you want. You can do jobs for money. You can scout for wrecked ships and raid them for their cargo and weapons, you can mine valuable materials from asteroids, you can cause a lot of wreckages, you can even take cargo from one station, where it is incredibly cheap, to where it is incredibly expensive and make busketloads. Naturally, the way you choose will depend on the ship your flying. Flying freight in a Heavy Fighter may be easier, but you will earn less. Likewise, accepting a mission to destroy some ships in a Freighter is stupid, as this will unaffect how much you get.
This brings me to the only downside to Freelancer: the inability of some purchases. As you fly your ship everywhere, you can only own one ship at a time. Buying a new one immediately sells your old one. You are also unable to buy anything that would need more than one person to fly. Those of you wanting to buy a battleship from the get go will have to wait.
Freelancer is a very innovative game. Combining the free-roaming capabilities of GTA with the space combat and cool ships of a series of Star Trek doesn't seem like a good combination, but it can work. Freelancer is a perfect example of this.