The only problem I'm seeing with this one is the kitty's right eye, which looks a bit sunken, and maybe a little too small. Perhaps it's just a matter of perspective, but I'm not entirely sure. Other than that, however, this is a really good picture! Simple, yet pretty and neat. The cute, plain background is just about right. You didn't need to add too much effects to make it look nice, which is what I like so much about it. Hee, this actually reminds me a bit of Alice in Wonderland for some reason. Good work, I like it.
Wow. I love almost everything about this. Anatomy, Shading, The way you played with the colors. Real beautiful. But here's a question: Where are the cat's front limbs? The pose it's in honestly makes me think it might be being held up by someone by the belly. I don't see how you couldn't have made the dark lines between the limbs against the body like you did with the splitting of the muzzle under its nose. I also think the collar needs more shading and you could add an actual background, But nonetheless it looks good. Keep going and improving!