Left and Right Arrows - Change Option
'z' or Enter - Select Option
Select various options (such as 'Feed') to advance time and score points by creating new organisms. Options have in-game descriptions.
The death of any category of organism (Plant, Herbivore, Carnivore or Scavenger) will cause the Ecosystem to collapse.
Simple - The basic game with one of each category of organism.
Evolve - The timer counts down until it is time to evolve! This adds additional complexity, but is not feature-complete :(