Ever wondered why you can't grief on the server? This is the time to shine. Players have a grace period of 5 minutes to build Tnt cannons (creative mode, don't allow debug switch) and test the redstone skills you have! The main goal is to send so much TNt it destroys the redstone torch in the middle of the 50x50x50 island(singleplayer) or 100x100x100 tnt island!
Vote high on this one!
Smaller island, 3 stacks of tnt and 5 mins of grace time and 1 redstone torch, material stone
Bigger Island, 5 stacks of TNT, 3 redstone torches and material is iron blocks