This will change the way you view SuperFlat survivals. Basically, this has everything a normal world would have (Abandoned Mineshafts, Strongholds, & Lava Lakes) in three blocks (actually, some structures are in the air!). The challenge is survival.
My challenges for you are as follows:

-Keep Moving; If you stop, don't make it longer than a Day/Night cycle.
-The Minecraft Project; Build a house with a door, windows, & a light source.
-Spawner De-Spawner; Break 10 Mob Spawners
-Minecraft Traders Inc.; Trade 5 things with any villager.

-There are Other Worlds; Go to the Nether & the End.
-The Enchanter; Enchant an item.
-AntVenom's Dream; Find a Golden Apple
-Diamonds Everywhere; The Quest to be the Best ends with Full Diamond Gear.
-Retire in Peace; After beating the EnderDragon, settle down in a NPC Village.

Oh, by the way, this is in HARDCORE MODE. Don't screw up.