Inside one of the hacks with the worst level design ever (Bits and Pieces), there is a level where the trees obstruct the sprites. It was one of my favorite levels. I think the problem with Fez 2 is more so how Mario behaves with the tree slopes.
i.e. have the trees solely for the purpose of blocking view of the sprites (which are placed in positions where you can see them at first), and have Mario walk on forest ground. From the screenshot, this seems to be what you're doing, so