here's my little MEGA65 implementation of the "Wa-Tor" population dynamics simulation
(see https://en.wikipedia.org/wiki/Wa-Tor)... start it from C65 mode and enjoy
P.S.: Source code is here: https://github.com/steph72/m65wator ...the whole thing is written in C, and compiled with cc65. Although it's quite fast and I did every optimization I could think of, the speed would of course be even better with a 45gs02 optimized compiler...