I really like the way you've made this and the detail as well as the textures make this look really amazing!
I like they way you've made the background very detailed with texture. The cracks in the dry soil and the bark on the tree look very nice. I like how you used the smoothness of Diglett to bring it into focus. The smoothness, although nice to make Diglett stick out, doesn't really go with the rest of the highly textured background. He just looks a little out of place, whereas if you added some texture to Diglett it may have made a more unified piece. I like the way you've made the clouds look very realistic as well.
I really like the ways you've coloured and shaded here. The colours all seem correct and work nicely. The shading and colouring with the textures really made the overall image look nice. You also gave a nice general direction from which the light source was located which is a good step to creating good shading. You have given many levels of tints and shadows to the original hues. No real issue here
No real problem with Diglett here.
In the end this is a really nice picture for Diglett, although I'd suggest just trying to make your piece more unified. I will give you a 65 on this. Have fun with your Diglett and please continue with your art prowess!