In this map, you have to survive, build a nether portal, find the end, and beat the dragon. Like in any normal game. But,....
The only problem is, you cannot craft any pickaxe.
Wooden pickaxes will be transformed into flint and steel, the other pickaxes will give you an amount of TNT (this is done with command blocks, so you will have to enable them in the properties).
At the spawnpoint you can choose the difficuilty, easy or hard, if you press the hard button i recommend to run away after pressing the button (you will see why).
The world generation is also changed a lot, how deeper you go how better the layers of resources, how deep will you go?
Recommend to play on hard (or hardcore), and don't cheat (which should be almost impossible anyway).