The real shame here is that it shares the first part of the title with Cities:XL and XXL.
I don't get why they couldn't have called it something else like just "Skylines".
apparently it's because it's a sequel to Cities in Motion. But, yeah, it's confusing with two different but similar franchises named Cities.
Having not really looked into this game much, I totally had assumed it was a sequel to Cities XL, and I'm probably not the only one.
Can confirm, I too thought it was from the Cities XL line of games.