Just push the play button and watch. The pink creatures are the pray and the dark green dots are the predators. Each of them has a 3 in 4 rate of reproducing and a 1 in 4 chance of them having twins, making a 1 in 4 chance for not reproducing. I added a chance for survival for the prey as well as adding plants. I removed the music and added a background changer. Background 1 is the one you start with while background 2 is just plain white. Simulate natural selection, overpopulation, and absolute craziness in this fun and entertaining game.
Thanks to @MrKyurem for their evolution simulator and inspirations.