The final step to completing the fatal puzzle is presented when another Splicer appears at a balcony overhead and starts hurling grenades at the player. Again using telekinesis, the explosive devices are caught mid-air and subsequently dispatched in the direction of the rapidly incinerating Big Daddy. A couple of well-aimed grenades later and the Daddy finally concedes defeat and collapses to the floor.

Before the demo ends, the player approaches the terrified Little Sister (who has been screaming throughout and is now cowering in the shadows), pulls out a wrench and stands over the petrified child with ominous intent. Levine poses the question (in a rather sinister tone): "Are you her best friend, or her worst enemy?" Unfortunately, we'll have to wait for another demo before we find out the implications of that particular moral dilemma.

Above: By turning Rapture's own security drones against the Big Daddy, the player is able to even up the odds

Levine is quick to point out that this demo only skims the surface of what lies beneath BioShock's murky waters. "Imagine the game with all 50 plus genetic modifications, all six modifiable weapons and different ammo types, hacking and crafting, all this great stuff... We're really trying to move the first-person shooter forward, and we're doing it through player choice."

We had already fallen for its wonderfully ramshackle Art Deco style and creepy neon-lit shadows - the evidence of a once prosperous society struck by tragedy - but after witnessing the mind-blowing versatility of combat, BioShock has well and truly blown our excitement gaskets. We can't wait to submerge ourselves deeper.