Know what you mean. Coolest thing to watch their ecosystem evolve in ways you can't fully predict.
At one point rigged some of mine up to be interactive. Seeing lifeforms reacting to my mouse was very odd. Then they evolved to eat the mouse... The boundary we imagine blurred for awhile though.
Keep thinking to go back to it. Freshen up the concept with modern neural nets(to develop at least the initial lifeform programming language) and an AI director to step up the environmental challenges.
Had decent success doing some manually, but feel we are missing the secret sauce needed to keep it from getting stuck.
We provide them numerical values for their senses. Programming code for collision detection(sight, touch, feeding) was pretty complicated though.
I don't know if they "feel" anything in doing their comparisons, but they certainly are happy to attack if they see something is near them.
Should note that they are not what we see. What they are is an array of data and ultimately the electrons on the chips.
May want to look at mental models and the use of simulations in our own brains. Whether they think or don't think, I'm not about to start discriminating between our respective simulations. The map may not be the territory, but it can be near enough to be interesting.