Click the green flag You can either go straight to the game or change the options You act as the predator and you must click on the leaf creature things to capture them. For each creature you get, the counter adds a "fatality point" towards it.
There are two leaf-ish creatures, one brown, one blue. The brownish orange type and the light blue type. You are the predator, and the blue creatures are easier to find than the brown ones. Although this isn't the best simulation, what would theoretically happen is that the brown ones will eventually thrive, as they're harder to find, well the blue ones will stand out too much and become rare.