You control a small monkey that needs to fight off the other monkeys while finding bananas. This is done as in the real world with poop trowing (yes you read correctly). At some point you are not only fighting the monkeys, but the evil zoo keeper will also try to catch you to get you to his lab.

You control the monkey with the left right arrow keys. By pressing A you trow a poop, or if you are walking while pressing the key, then you start running. If you press S you jump, and if you press the up-key while jumping, then you can grab on to the branches and vines.

Source: http://www.schulz.dk/en/projects/poop/