It really depends upon where you want to set it. Where is this place? Is it in a jungle (dense leafy plants, vines, trees); desert (cacti, coarse grass, tumbleweeds); badlands; tundra, etc? Look up photo reference of similar places on Earth to get an idea of what would be in that environment. At the moment it's difficult to really tell what kind of environment its supposed to be, so it's hard to really make suggestions. Once you decide on the setting I think it will come pretty easily.
I think the tops of the platforms could use a bright colour added to increase their contrast.