The gameplay highlighted the game's "strategic dismemberment" combat--requiring players to tear enemies limb from limb.
Also shown was the game's holographic heads up display, which projects weapon and item selection in front of the protagonist, with Isaac moving his head as items are selected.
As previously reported, there will be no persistent on-screen HUD. Instead, Isaac's health is indicated by the light on his back, with ammo count only being displayed when a weapon is readied.
Check back with Shacknews later this afternoon for video footage of the demonstration.