The download sizes do suggest you&#x27;re downloading a whole game, or at least most of one. This does not, however, imply that the game is ported -- just that they pull the game from the server rather than the disc. This makes sense even if they&#x27;re emulating, because most Xbox 360 games will have received a lot of updates compared to what&#x27;s on the disc, and Microsoft have probably only tested the emulation against one specific version.