Gameplay. If I cant play it well(through no fault of my own) any game would be unplayable for me.
For example: BF3 Beta. The controls just don't work good(I understand it is a beta not a demo, but it was the first thing that came to mind).
They fixed allot already, the beta was 2 months old by the time of release, read this review of BF3's new, but not actual retail version of the game.
http://planetbattlefield.gamespy.com/View.php?view=Articles.Detail&id=29&game=15
Sorry if that got a bit of topic, on topic i think content and game play is a must before trying to have graphics like BF3, Crysis 2, or even what they have now.