You should try to limit your colors, don't add any unnecessary shading.
I think for rocks for example is a step back, the previous ones works much better with the cartoon style.
If you can draw something with just a few shades it will be easier for the viewer too. Force yourself to simplify shapes and really think about the depth.
Also, exaggerate the sizes, it's hard to tell the shape of the stairs when it's just a few pixels for each step.
I had another go at it, a lot of experimentation and I don't think everything in there worked out..
But you should look closely at the house on the left and how I added a bit more depth by offsetting the beams.
