Game allows players to build outlandish medieval siege engines to pit against castles or armies. Players select from a collection of mechanical parts that can be connected together to build a machine. Each level has a goal, such as “destroy the windmill” or “kill 100 soldiers”. Although the goals are relatively simple, the wide variety of possible approaches allows for experimentation. Despite the medieval theme to the game, players are able to build modern vehicles such as tanks, automobiles, bomber planes, propeller planes, dirigibles, and battleships.