You nailed the retro feel, and the gameplay is fun. I could definitely imagine this in an arcade cabinet somewhere. There's a lot of attention to detail, and some surprisingly interesting tech and strategy for such a seemingly small game (for example, you can clip diagonally through walls in the second level, which I felt really smart finding out). Layout-wise, I preferred level two. I never figured out the animals, but I'm sure I'd recognize some patterns if I played longer.
I do think that the art is kind of strange, and it definitely threw me off at first. It looks too much like a building to me. Maybe the ground can be green grass and the walls can be a blue river passing through. Maybe the second level can have tan sandy ground and gray rock walls. Just some suggestions, of course. Well done :)