First BioShock Infinite gameplay footage (video)

The trailer shows a little under 10 minutes of gameplay in BioShock Infinite's floating city of Columbia. It's all about exploration and atmosphere until, about three minutes in, the player picks up a rifle from a barrel... and is immediately attacked by an old man who summons a flock of crows. The rest of the video is very action-packed, with some sections involving sliding around a rollercoaster-like rail system that connects Columbia's different floating islands.