Thanks for trying it out and the great feedback! The point about tetris is definitely a good one, I should make the "correct" way to play more fun and rewarding. Something as simple as point values popping up when an animals eats another one or something would probably help.
The reason the win conditions are what they are now is it's the "real" problems an ecosystem faces, IE: losing a key predator/prey animal can de-stabalize the entire food chain, same with over-population. Maybe that would be more clear with good assets and an actual animals for the shapes.
I really appreciate the feedback, you've given me some good inspiration for games to study and take lessons from!