This game is rather great in it's way,but there's some issue going on in the game, basically I close the app for about an hour and once I came back the map I recently used was changed into another one, I was confused why,so then I tested the app by closing the tabs a few times,the maps kept changing into different ones I didn't even unlock yet. I just unlocked all of them with the in-game money. I would rate this 5 stars if the problem was fixed.