I played the demo to completion, but I doubt I'll ever get the game. It looks beautiful, I love the dragon controls and skill advancement system - but ultimately the game seems hollow, to me.
I got no sense of purpose behind the dragon's actions - no reason for him to be helping the humans. And the level of actual interaction with other creatures appears to be non-existent.
Beyond collecting crystals that give power ups, there isn't any sense of building up an inventory of useful items or anything like that, either.
A great gimmick - but judging by the demo, NOT a great game, IMO.