The multi-platform construction and battles game has become a worldwide phenomenon – so much so that it can draw thousands to live eventsAs a corporate conference venue, London’s ExCeL Centre is regularly overwhelmed by besuited executives dealing in arcane business jargon. This weekend, however, an altogether different sub-culture was in charge, as Creepers, Zombies, Skeletons and thousands of children congregated to celebrate a common digital passion: Minecraft.Minecraft involves exploring a world made out of digital blocks, which can be broken up and made into new materials and structures, from pickaxes and swords to buildings and carts.