This one is another game in the long line of community building games. This follows the basic model established by the Build-A-Lot series. You have a large neighborhood that you have to improve with new houses, businesses, and infrastructure. You can then get new upgrades to increase your wealth and meet goals. While you are doing this, you'll have to manage your money and supplies to keep the construction going as planned.

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The reason Plan It Green is at the top of my list is that it seems to have perfected the formula behind the games. The premise is that you are trying to renovate your town into an environmentalist paradise. You are still just putting on new upgrades and building new buildings though, if you aren't too motivated by the "Green" plot.
The nice thing is the intricacy that it adds. For example, there is full scale zoning in the game. You have to place commercial, industrial, recreational, and residential buildings in the right places. This also grants a bit of order to the game. Your changes also stick around. There are several districts that you work on for the game. Return trips have the same map with the town just as you left it. This makes your actions seem like they have consequences. Finally, there is a separate system of energy credits where you can sell the power generated by your solar panels and energy saving measures.
Overall, it just seems like they got it right.