Just checked in mine. The app itself weighs in at 1.3GB, and that doesn't include setting or other stored documents it may create. Meaning it will take awhile to download, especially if your Internet link is not fast. And if it is flaky and the download process fails in the middle, it will need to start again from the beginning. So what you may end up needing is patience. Lots.
My home ADSL 10Mbps link takes over 30 minutes for a download of an app this size. Infinity Blade 3 (2.8GB) took quite a bit more. Just saying….