If there is any lingering doubt about the sheer magnitude of Halo, it is eradicated in an instant. Here we are, in a plush West End hotel, with Channel 5's The Gadget Show presenter Jason Bradbury as host, to get a hands on preview of a multiplayer beta. A multiplayer beta. If this were any other game you'd think, "whatever". But then this is not any other game. This is Halo.