Before I go further let me state that I am a college Biology Professor so some of my points may be more than the game was intended for.
First off I played using 2 starting "home" cards that could be any habitat but were set on one habitat once the first card was played on it. I also used event cards that said habitat as though it affected the terrain of the organism it was played on.
First - problem that we arrived at was does a card that is a bridge between 2 different chains have to fit both or only 1?
Second - do the chains have to feed all the way back to the originating "home card"? The example we had was a photosynthesizer was played on a level 3 carnivore and the carnivore got wiped out from an event so does the photosythesizer stay or is it also wiped out?
Third - many of the carnivores in real life are able to eat things many time larger than they are - e.g. Wolves eat Moose but that is not in this game. Also there are many that cannot eat things within one scale of themselves - e.g humpback whales would die trying to eat something one scale smaller they must eat soemthing about 5 scales smaller. I changed text on some of my cards to fit this bill because I just couldn't put a Swan eating a raccoon (or something like that).
Forth - I had a hard time with the "MOVE" since it seems like everythimg is a 2 except for plants. So I don't think any of the times I played anybody used it because everything could just follow. Wolves and Caribou are going to move much farther than a mouse (I am thinking of home range).
Fifth - many of the event cards don't seem very viable and in many games they weren't used at all, which shouldn't be the case since things always happen in the environment to change things.
Sixth - many of the point values for cards didn't seem to make much sense. With one card getting 8 points and another that seemed harder to play would only get 6.
Seventh - I think there needs to be a different method than color to denote feeding type - e.g omnivore, herbivore, photosynthesizer etc. If I use this with a class it will have to be black-and-white because I can't afford to print all these out in color but then you lose that information.
Eight - the "Spread" seems like a cool idea for plants but I am not sure how it works in this game. I would think that if a pollinator were played next to it then that card could double and grow to fill in another spot giving that card holder double points (not sure how to indicate this in the game unless an upside down card is used as a marker.