It's meant to be a demo. The game so far is completely campaign driven (no "go shop, get items, hunt, game over"). I think it will be more fun playing with friends aiming to finish the game, rather than walk around the same area 99 times.
Edit: Yippee, beautiful room transitions. The beginning of the game feels very natural, from an almost "akward" situation to an upbeat awakening in the game's main town (which is yet to be finished). The game, I can confirm, uses many Mp3 files, which may have the demo resulting in 10mb. Maybe lower, I don't know how far I can take it, but I have until August. The reason I'm using Mp3s is because it was not meant for online downloading, but just getting the highest marks possible in school.