Having the UFO slowdown while carrying bricks was a good touch. Made me think about how far away I wanted to have them while I was building my cities. I agree with the comment from another user about having the UFO snap to the grid. I had some moments where I dropped people off in the wrong square.
Also was unsure of where the barbarians were going to attack. It seems like they would start attacking the pyramid at the first opportunity, but they would move past the corners so they could attack from a specific square. Seems counterintuitive to an enemy AI.
Overall I enjoyed the hustle this game required. It kept my head on a swivel with it's fun and fast-paced play.