The BioShock demo popped up on XBL today, August 12th. It’s had some very positive reviews by those who’ve seen the pre-release product, so many of us are holding out high hopes. It’s, in short, a sci-fi game set in an underwater, Ayn Rand-inspired Utopia called “Rapture,” which is riven by civil war and rampant genetic modifications and experiments. The theme appears to be very 30’s and 40’s retro sci-fi, and it’s a first-person shooter. Available for download now.