How to "Win"?

[J B Dryden]

Can I only "win" each of the maps by unlocking each of the building types?

[Greg]

I think you can win any map following one of the the paths that unlocks at the beginning of each game.
Not sure if it is that way, still trying to finish my first city....

[GeoCaprican]

There are 3 Achievement paths to 'win' the map: wealth, productivity, and leisure. You can win any map with any path, but once you 'choose' a path you must stay on it. Check the little star icon in the upper left corner to see what you need to build or produce to unlock each level. I think there are 8 levels?
So far I've found the Productivity path the easiest and have yet to finish the Wealth path. But you need to check the Achievement panel early if you have a particular path in mind; depending on how you play it's easy to fall down a path unintentionally.