This same "AI ecology" principle (as Irrational's calling it) means that once you know what rules the characters adhere to, you can pervert their behaviour in other interesting ways, such as fooling a big daddy into thinking you're a little sister - thus protecting you to the death - while another example showed how you could remove a guarding Splicer by using a security beacon ability to draw the security bots into attacking it. Almost every minute of the demo had something truly impressive about it, and left you in no doubt that Bioshock will be something special.

With a fantastic attention to detail, the game also leaves clues for the determined player, such as audio logs from dead citizens of Rapture. In the final section of the demo we're shown a record store with the knowledge that a particular musician we need to flush out of hiding has an obsessive hatred for a rival. Once in possession of that recording, viola - one crazed composer literally faces the music.