I am disappointed that Common Sense Media gave this Zynga "game" a high score.
It is their same basic Zynga concept. Click to build things and if you want to build them faster you need to buy some Facebook Credits.
I suspect whoever gave this game such a high score just saw a kid playing it for five minutes. You'd be better off finding a discount version of RollerCoaster Tycoon if a kid wants to play a real game.
Zynga games are not games, most of the time. They are either identical to board games or the same "FarmVille" experience with new backgrounds.
FarmVille, FronteirVille, etc. Don't waste your time, and most certinaly not your money.