I inch my way through Spelunky [official site], trying to get a read on the layout of each randomised cavern. Caution doesn’t always breed success and I rarely reach the ice levels, let alone the hellscape beneath. It’s both chastening and invigorating to begin a weary Friday morning by watching a speedrun that sets a new world record – from start to finish in 3:44. The runner is D Tea and he shatters the previous 3:52 record for a true ending. As well as being an impressive feat, like most things Spelunky, it exposes the workings of the various systems – from the fury of shopkeepers to the arrangement of tiles – in fascinating new ways.