I'd give you 7 stars for the graphics alone, the quality and overall fluency of the animations is one of the best ones I have ever seen.
But - as said before - the game is actually very easy. There is only one correct way to finish it and you have to use every option provided (just the order matters). That's why we don't really need those white circles, let us to figure things out by ourselves.
As for the plot - so there is one main generator for the whole city (of course it can be freely plugged/unplugged) and when it's off, the whole town goes to sleep? Really, no backup system?
But aside from this, the game is very nice, I enjoyed it.