Click on the cat you like and watch as its genes are passed on to the next generation of cats. You get to play mother nature and select for certain traits, which are pixelation, brightness, size and whirl. The replay button shows a small animation of the evolution of your cat and ends the process. The variables are toggleable.
This is much simpler than what I originally had in mind but whatever, it kinda works. This is meant to show how selective breeding and genetics work (of course it's much more complex irl but I think this gets the general concept across)