I see you've created obvious perspective platforms - the top, walkable surface of the platforms is visible, as if the camera is slightly tilted down. So far though, all walkable tiles are pretty much straight-on profile platforms.
If these tiles are all meant to be used together, should they all be one or the other, and not a mixture?
When I see those bg tiles, I immediately think Cave Story. If they're not lifted directly, they look like it, to me.