In terms of art style, this is a highly versatile foreground that is compatible with a broad spectrum of other graphical elements; it's very reminiscent of SMAS in that regard. On the other hand, there are some rather strict limitations on how the tiles can be used that I found rather frustrating when I tried to actually design a level with it. The most egregious was the absence of slopes, which puts a hard limit on what kinds of level design are compatible with this foreground. The "ruins" tiles, meanwhile, can't really be used to construct anything other than one- or two-tile long platforms; it's hard to imagine them being used to create any kind of credible "ruin" aesthetic. The black rock walls are just solid tiles of a single color and look bad if used to cover any large part of a level. While the rock "arch" formations are nice-looking themselves, they can't really be used for anything else. It would have been nice if I could use them to add a little bit of texture to the solid black tiles, but all attempts to do so wound up looking odd. While I appreciate the availability of three different colored crystals at four possible angles, I think that at least some of the 72 tiles used for them would've been better used for additional textures or slopes.