So the left over footage from PAX includes a few minutes of Demigod footage with some detailed developer commentary. The explanations highlight your demigod's character development as you play - the big old central unit in your battle will grow stronger and expand in powers during each bout against another demigod. So it's that whole RTS-but-ooh-we-have-RPG-stats-for-heroes thing. The footage also give you some idea of how the game plays - a fairly fast-paced action RTS, via way of the tower of Babel and cosmic battle-chess. It's looking good.
The limited beta, which should begin any day now, will be available to folks who pre-order via Impulse.