I was really drawn in by the art. I liked the fog on the cover image. I was little lost on how to upgrade. The disabled/you can’t afford button graphic didn’t read as I couldn’t click on and I thought I found a bug at first. Then realized that I didn’t have the right level of building yet. Maybe if the whole row could look disabled that could help? Or the disabled color darker and the enabled color brighter? I also didn’t realize at first there was any music. I had to turn my speakers up quite a bit to hear. The fog effect looks excellent!