Notch and Jens/Jeb should make a mode where you spawn in a group of paleolithic nomad hunter-gathers. Animals are less abundant, and monsters spawn more and do more damage. There could be animals like bear and deer, but with bear and wolves they are hostile and wolves spawn in packs and bears alone. You can catch diseases. You can only hold 1 block in your inventory and once you dig one block you cant dig another block until you place that block down (workbenches and furnaces don't count). Therefore the group of nomads is essential for shelter. You can gather berries/nut/herbs/etc. You spawn with stone tools but they don't wear out. And a new game aspect for this mode: exhaustion. When you sprint your exhaustion goes up. If your exhaustion goes up to 100% you die. Exhaustion goes down at a very slow rate when walking but a decent rate when being still. And when you die the world is deleted. As for the exhaustion, when your group travels they sprint, walk, sprint, walk, sprint walk, until they reach the destination. Therefore if you don't go at the same paste as your group you will get left behind to die during night.
Anyone else like this idea?