Quickly swipe your cursor across the guy to smak him. Beat the guy up by smacking him repeatedly. The damage score is contributed to by everyone. Damage dealt is determined by how hard you smack him.
V1.1 The wobble physics is just the sine of a constantly increasing variable linked to a fisheye and whirl, which uses a glitch to make it squash and stretch @Kqax for score counter because I was feeling lazy