Lovely style but a lot of the tiles get abruptly cut off at the bottom.
And yes, you really need to play around more with depth and shadow to make it easier to make out shapes, walls and height differences and see where you can walk.
The character and a lot of the tiles seem to have the wrong angle.
You should show more of the top side, like make the signs 1 pixel thicker at the top, since with this perspective you're looking down from above and not straight in front.
[EDIT:]
Attempted a rough edit, just experimenting really, lighting is not very consistent.
But notice the thickness of the signs, the shading of the rocks.