How do I get rid of 'game of war' pop-up from the app store?

I was browsing reddit, clicked on a link that directed me to imgur, and after a few seconds I was redirected to the app store where Game of War popped up. Now I can't navigate away from this app pop-up in the app-store, and I really don't want to download it. I've cleared my cache and cookies, but this makes no difference. I would delete the app store and reinstall, only that's not possible.

What can I do?