SubaraCity

50 million points should be the minimum that you need (thanks to CLARION 85 for telling me).

A level 29 building needs 20 level 10 buildings and gives you 70 million points. That's how I got the achievement.

I played on casual. You only have three colors which makes the game a lot easier. The downside is that you only have one mayor and don't get any extra. You can't make any mistakes! And you need a bit of luck. It took me several attempts.

Some tips:
- Work from top to bottom.
- Don't make level 10 buildings in the middle - do It like an U instead. They can't block your playing field if you stack them on the side and bottom.
- Don't combine level 10 buildings unless you got 19 or more. One level 10 building more can double the score. That's how I went from 16 to 32 million in an earlier try.
- Don't make level 10 buildings right away. Look around to see if you can make a larger combo. Emptying the playing field gives you new blocks and can save you.