Good graphics but this game is designed to suck money out of your pocket.
Upgrades are the most expensive of any other game that ever been released.
Worse still is the wait time for these upgrades.
Imagine an upgrade that can take 4 hours, think that's long ? Try 4 days.
And as you level up they become more expensive with even longer upgrade wait times.
Reason they do that is so if you don't want to wait you have to use a form of currency called Crowns and these will cost you real world money.
They are banking that players will be impatient and don't want to wait it out and will pay.