Even after 8 years, I still come back for more. Out of all of the Sim City games, this has to be the best...
Although it may seem at first like some simple addition to Sim City 3000, the game goes above and beyond what most sequels provide in games. First off, you get two new building sets, one based of European design, and the other off of Japanese design (although it is defined as Asian, it has more Japanese/Modern influenced buildings). Indeed, the little shops and houses pop up in random places within their zones as usual, but they still look good. The new building sets don't change some buildings, but it is a nice refresh from the American building set (although it does share some buildings with the European set) and have skyscrapers that look a little different, and when the buildings repeat themselves, it's not really to bad looking.
Gameplay is essentially the same though, you'll have to build various zones, transportation systems, infrastructure, and public buildings in order to make your city functional, all the while keeping your budget in balance. Of course, the game has plenty of cheats, but indeed, some people do like to play fair.
Along with building sets, you can also change the terrain and flora that appears in the city. So now you can have that redwood forest for you nice little Euro town in the snow region, or build a replica of a Nevada town with Joshua trees. Also, you can choose to start your city in the years 1900, 1950, or 2000, all of which will give you or limit what kind of structures, power plants, and transportation systems you can build.
The advisers and those who wish for change or have an issue with your city are all drawn up political-cartoon characture style, indeed, a little goofy for some tastes, but all in all, still giving you sound advice for somethings and warnings of disdain for others. Still, they do not age, do not change with the building set, but merely just represent your office as a whole. Indeed, SC4 offers far more realistic characters for you to work with.
The game's soundtrack is very impressive indeed. Most of the New York City style jazz and Asian inspired pieces seem to fit too perfectly at times, but some of the new age tunes just really don't fit at all. Luckily, you can turn off which piece of music you don't like the most.
The sounds are also acceptable, considering that they are still used in some of the modern Sim City games,. Car horns, wind, the disasters, and many other noises don't get too repetitive, but sometimes seem a little too subtle in some situations. This is especially true for when you hear stuff from your highways and downtown commercial districts, or have space junk come plowing down into you suburbs.
There's also some nice extras that allow you to customize the game. The Building Architect Plus program allows for you to construct your own buildings, and even allows for uploading of custom textures and props. Of course, if you can't really build your own structure, you don't have to. The Scenario creator is also in, allowing you to try your hand at creating a scenario similar to those in the game. Of course, it requires scripting, understanding of what city you're going to be using, and a little programing knowledge to use, sometimes at the point of being too difficult to use. Still, these extras aren't really necessary to get the full joy of the game, unless you want to see a building with a Krystal billboard on it appearing in your city, or try to challenge others to keep a city alive after a severe disaster, then you can go for it.
There's an awful lot of stuff to cover, not all that I could explain here, but luckily, this game has a nice thick instruction book (yes, a wirebound BOOK) that's filled with the info needed as well as Maxis' attempts to get you to chuckle a bit.
Overall, Sim City 3000 Unlimited is still a good, solid game for those who found Sim City 4 Rush Hour to deep yet are disappointed by Sim City Societies. Indeed, even if you already have Sim City 3000, ignore what GS said, Unlimited is full of things worth trying it for. Besides, it's been around for over 8 years, so it should be cheap. The website may even have users willing to exchange cities, scenarios, and buildings still! If you want to build the ultimate city without extra hassle (or having people think you're an egotistical freak), then Sim City 3000 Unlimited is certainly something worth grabbing for.