Cannoneer.jar
-a player has an item in their inventory which should be buyable at a shop. When right clicked, it spawns in a premade cannon, which is maneuverable so players can switch ranges. I'd preferably have the cannon nice looking, but most importantly maneuverable. All that would be needed is TNT, than the player sets how far it shoots (doesn't have to be block for block).

It would cost TNT and have that handmade feeling, easy to use, shop, and perfect for Factions etc.