played through the E3 demo, really took my time doing it (29 minute clear time).
So far, its good. Its still clearly very early on, but the fundamentals are all there and all solid so far. The graphics ain't top-of-the-line awesome, but entirely adequate, the music is pretty ace tho. I have no reason to think that this whole thing won't turn out just fine, hell, just releasing the demo at such a large scale (over 40K people get to pick it apart) shows that they're pretty confident about their progress and where they're be able to build from what they have now.