Seconding Cyangmou that the rocks are too small. Even ignoring the scale problems, they create a lot of noise, making it harder to see the important parts - where the playable area is, and the details of the characters in front of them! If you don't have time to redesign the rock tiles, consider at least playing with their colours to help the scene read more readily.
I'd reduce the contrast on the background rocks, or maybe even use just the two lighter colours on it. The characters get lost against it.
I'd also make the borders between the tops of the rocks (in the walkable/playable area) thinner and perhaps use a 4th colour to make them lighter. As-is, it's not immediately clear what's horizontal and what's vertical because they have about the same value. Try creating the tops of the rocks with just the two lighter colours, using the 3rd colour very sparingly to create a little bit of extra depth.
Here's a small edit, I modified only the colours of the background rocks, and some of the horizontal surface to the right of the white cat:
Isn't it easier to tell what can be walked on and what's a wall like this? Personally, I'd go further by either adding a 4th highlight colour to the tops, or using the current lightest colour much more sparingly along the vertical parts, so that the playable area is even clearer.