You play as King Arthur in this game and just like in the game One Button Bob (you can also play on ArmorGames), you will have to finish all levels with as few clicks as possible. It can be addicting for it will test your reflexes as you try to make the perfect timing to click. The one who finish the game with smallest number of clicks will be crowned the One Button King. No, I just made that up. Anyways, here's a video of some dude who recorded a One Button Arthur walkthrough.