The stand alone player consistently slows down and eventually crashes as I play between 30 minutes and an hour, but it saves what your last build was and replaces it on restart so I'm not even mad. Though if it stayed stable long term I would definitely just set up an aquarium of little custom critters and let it run.
I would definitely watch that, love these little guys. I guess while I have you here I have one note and one suggestion.
The note is I can't seem to see, on standalone or embedded, uploaded creations past page 56, entry 1000, which ends in the middle Gs.
The suggestion is, and I don't know how easy or possible it would even be, I would love to limit color vision on eyes so that a creature could potentially recognize and avoid predation or sharing space on its own kind, which also opens up mimicry through camouflage.