I would like to say first and foremost, I recommend this game. It's pretty short and sweet, the art style is adorable, and the mechanics are unique enough that it sets itself aside from others.
With that said, I gave it 3 stars for a reason.
The progression never feels great. It's fine, the number is going up, but you never really get that "Oh hell yeah" feeling.
While the buildings are fun and unique, with built in widgets to give them bonuses, It feels like you get very little feedback on if you have a good build or not.
On the topic of the widgets, or "Devices" as the game calls them, these along with several other mechanics are never explicitly explained, and it can be very easy to miss them entirely unless you happen upon the help menu. I had several things I did not even realize existed until after I had beaten the game. A more in depth tour of the menus might have been a good play.
Again, for 3 bucks and a couple hours of your time, there are worse ways to spend some down time.