It took me some time to get an understanding of what I was meant to do. It was helpful that the controls were listed in the description below, and I didn't realize for a long time that I could move the trees. Occasionally the pathways would be spontaneously cleared out and all my traps and trees would disappear without warning. I think I'd like to at least have a clue that was about to happen.
Overall, the art is nice and the concept is quite original. The game feels hectic and it feels like you can't really stop the humans, only delay them.