The latest Ludum dare competition challenged developers to create a game in 48 hours based on the theme "Alone." Minecraft creatory Markus 'Notch' Persson has turned in his entry already. It's called Minicraft, a top down, 2D take on Minecraft. You have to roam the world, punching trees, blocks and zombies in your way as you try to find the only other sentient being in the world, the Air Wizard, so you can kill him.
You can play it in your browser here . It has a workbench at which you can craft better weapons, multiple biomes to explore and different enemies to kill. Equip the Pow Glove and hold down the X key for SUPER FAST PUNCHING.
Entries are still pouring into the Ludum Dare database. You can browse and play them at your leisure on the Ludum Dare site. The jam is set to end in 14 hours.