Well I got 11 after a few minutes of concentrated staring. Well, i think so, a couple were iffy, and seemed to go against the general trend of what the people were. The guy on the horse, and what looks like a fleshy face in the trees somewhere on the top left, oh and the half submerged face where you can just see the eye and which has 4 written on it's forehead. But I think with all those I found 12, so something has gone wrong somewhere
edit: also the ones in the trees look cool.