As for the space for the 2.4gb game i needed around 10gb so a little more than that for this one i guess. I would just find out but id have to uninstall all my games and lose alot of progress and data.
The other way that doesn't require large amounts of space that I know of was when the developer was making it a zip download where you move the large game file from downloads to the zimon document. But the zips stopped being posted a few updates ago.