Well, after this title screen what's more to say? :)
Anyway, the objective is to sneak behind people and then use the mouse to play a mini game, where you have to drag a line that the game instructs you to without errors. The thing is, both the sneaking behind and minigame happen at the same time, so you have to keep moving your character and move the mouse, resulting in much fun! Here you go, here's a link for you to try out!