- Disaster: UFO attack!
- Goal: 100,000 population after ten years
This scenario can be very easy or very difficult depending on how you approach it. It will be especially difficult if you don't realize that the frequency of UFO strikes is proportional to your population. They probably won't come at all if your population stays below 80,000. Of course, if you do that through to the end, you can't win because you won't have enough people.
Set taxes to about 9% and fire funding to 0%. You'll be dealing with a lot of fires, but you're going to put off the invasion until you have lots of money, and then you can just bulldoze firebreaks around the fires and not worry about fire coverage. Do keep fire stations, however, because a few will probably get blown up, and your citizens will get mad if you let the last one go down. (It's weird: they demand fire stations, but not that they be funded.) Do not build anything. Tear out extraneous roads, and also bulldoze a few police stations on the outskirts of town, where they're not doing much. If you bulldoze a few too many and you get a crime problem on the outskirts of town, and there are only a few sparse and underdeveloped zones in the area, you could just bulldoze the zones and get rid of the roads there, too. Crime problem solved. Just let your city sit there. If a plane crashes, by all means put out the fire and rebuild, but don't go building other new stuff. Your population will probably constantly fluctuate between 60,000 and 70,000 people, sometimes dipping considerably lower or rising considerably higher, but it will generally stay near that range. That's OK, you should be making plenty of taxes (at least if you set them to 9% as suggested).
When there are about four years until the end of the scenario, you should have over $30,000. This should be plenty. Chop taxes significantly; you won't need the income anymore. 5% should be a good, stable rate. People should start trickling back into your city. Start zoning, first filling up the gaps. The aliens will probably come shortly after you get 90,000 people.
The first time the aliens come, you will be hit hard. They will take out many of the casinos, which is one reason you don't want to provoke their wrath too soon, because those casinos bring you significant income. Bulldoze around the fires, get rid of the rubble, and wait for the fires to go out. Fix up power lines and build more zones of all kinds elsewhere in the meantime. Get rid of industrial zones that are too near the city center, replacing them with residential or commercial zones. When the fires start to go out, rebuild there if it seems desirable. You'll probably encounter more aliens, since your population will still be rising, but you'll only face three per wave. They probably won't bother you too much, and they likely won't show up at all in the last two years of the scenario, no matter how well you're doing. By the last year, your victory will probably be assured, but you can lower taxes to 0%, build more police stations, and so on, just in case.