Changes from older Sim City
So much hustle and bustle!
The first thing jumped out at me about SimCity 3000 is that the city is literally alive with activity. Contrast that with the original SimCity and SimCity 2000, where things were more or less static. In this latest version, you'll hear the hustle and bustle of a city in all its glory. Sprinklers bathe lawns in water in your residential areas. Cars roar along and honk their horns. Trains rumble along your railways. Factories sound off their heavy machinery. You'll see families pushing strollers near parks, police chasing crooks in high crime areas, smoking pipe stacks in your industrial areas, and wheelchair bound residents near the hospital. The level of detail in the game is nothing short of astounding. Maxis included several levels of zoom in SimCity 3000, and in the two or three more close up ones, you'll be treated to these detailed animations of your citizens in action.

Extreme zoom - notice the traffic on the left?
Zoning Densities
Another thing that's new is the density level of your zoning. In the first SimCity, there were just three kinds of zones; residential, commercial, and industrial. The density level of those zones changed automatically depending on your population level and if you packed them close enough together. In SimCity 3000, each of the three zone types can be light, medium, or heavy density. A light density residential area, for instance, would yield single family homes like you would see in suburbs. A medium density residential area gives you smaller sized apartment buildings, while heavy residential gives you incredibly tall skyscraper apartment complexes. Heavy commercial will spawn tall business skyscrapers like the kind you see in downtown LA, San Francisco, or other big cities. In fact, there are over 400 different building types in SimCity 3000. This contrasts with the merely 80 in SimCity 2000. With so many buildings, your city never looks monotonous. Maxis also brags that SimCity 3000 makes sure that all the buildings nearby each other share the same look so that your zones don't look like a random hodgepodge. Apparently there was less control over this in previous SimCity games.
Advisors
One new feature I found especially useful was the interaction with your various advisors. You're given several advisors who are experts in areas like finance, transportation, safety, and environment. Depending on the condition of your city, these advisors will notify you of problems you're having and the steps you need to take to correct the problems. Even if things are running smoothly, the advice of your advisors is just a couple of clicks away. They'll even give you tips on items like ordinances (should you give out parking tickets to raise money? Enact a youth curfew to fight crime? Legalized gambling?) you can enact, and show you the pros and cons of everything. There are also briefings from each advisor on many issues that help you play through the game with as much knowledge as you need to make informed decisions. Think of them as a virtual cabinet department.

This guy helps you with transportation planning
Neighbor deals
Interaction with neighboring cities will play a key role also. If you connect power lines, water, or roadways to your borders, then you can buy and sell services with your neighbors. If you have excess water production, a good way to make a profit is to sell your water to your neighbor for a monthly fee. Watch out though, because if you cancel the deal or your pumps can't keep up, you'll take a big financial penalty. The same kind of deals can apply to garbage disposal or electrical power. The only problem here is that you can't initiate the deals yourself. You have to wait until you're solicited for one by a neighboring mayor.