Sorry for this problem! We just posted an update today that should fix this. Please download it and let us know if it helps!
Here's how to update:
Go to the Windows 8 start screen by pressing the windows key on your keyboard, or pressing the windows button on your tablet.
Tap the green Store tile. If you can't find it, you can type the word "Store" on your keyboard to bring it up.
In the Store, tap the green text in the upper-right corner that says "Updates". This appears whenever any of your apps have updates available. If you don't see it there, all of your apps (including this one) are already up-to-date.
On the App updates screen, tap "install" at the bottom to install all of your available updates. If the game appears in the list, then there is an update for the game available, and you'll need to tap this game's update listing to get it.