-Not fond of the lack of rollback.
-Not too fond of the clicking X to close popups either. And, so far, the popups seem a bit redundant, but maybe the developer is just testing the technology and intends to remove them from their current use, but actually use them elsewhere.
-Whether sandbox is a good choice or not, we'll see. Few games ever benefitted from sandbox mechanics, but I'm not gonna judge on it right away, because a few games is still more than no games, and it's always possible for this game to turn out to be one of those few.