The idea was: Prisoner's Dilemma competition, but with evolving strategies. Watch altruism and loyalty emerge from the law of the jungle.

This prototype is running entirely in python (using pygame). It does have quite some bells and whistles, optional sexual reproduction and elaborate sexual selection mechanics, as well as cultural and tribal ingroup/outgroup behaviour.

But it had to be redone from scratch, because the Prisoner's Dilemma strategy encoding was just too smart for its own good, and thus evolutionarily unstable (with reasonable strategies hidden in a sea of nonsensical ones in evolutionary topology).