lost in a sunbeam

I really like the overall atmosphere of your artwork. Very well done. 

You created a feeling of depth by decreasing the amount of details in the background. That's very good, so the eye of the viewer doesn't get distracted from the main part of your drawing, the character. You can push it even more into the distance by using less saturated colors in the background.

The pose of Sedgekit looks very nice and cute. The anatomy is correct for the most parts, but the hind leg looks a bit off in my opinion. Try to search for some reference photos on Google (or the search engine of your choice. ^^) next time. Analysing the skeleton of a cat in this case can be really helpful to understand how the body works.

Since the sun is almost behind the character, the shadows on it's body and on the ground should be much darker and the highlights on the fur on it's back closest to the sun even brighter. The shadows and highlights you put are correct, but you could increase the 3D feel and depth even more by following these tips. 

Another nice touch would be a foreground. Maybe some dark blades of grass on both sides of the picture. So you would have a foreground, and not only a middleground and background.

Again. The picture looks great and you should keep up your good work. I hope my critique is a bit helpful.