I downloaded it yesterday and got 35 notifications overnight (lots of requests to play the game, I don't know how to change it so I don't get random requests). It's pretty darn annoying. Surprised you're still getting notifications after uninstalling it. Did you restart the phone?
My sister had the same issue (notifications in the middle of the night with the game uninstalled), so she went into the Games hub, into the settings, and shut off game notifications. They stopped after that.