You did a very good job, but I can see a few things that could be touched up on.
The cat's chest is facing us, but the entirety of it's side is visible. It's back wouldn't be able to twist like this so we should either see only part of the chest, or part of the side and back.
If you chose to keep the back instead of the front-facing chest, I would add a little more exaggeration to the back and maybe lose, or change, some of the fur detail. With cats, the elegant curve of the back is very noticeable.
If you decided to keep the front-facing chest, the back and hind legs would be behind it, though the curve would still be visible, of course.
The legs themselves are a little lumpy, compared to the graceful lines a cat has. The heels should be lower, and at a less extreme angle, while the knees would have a slightly shallower curve that blends gracefully into the body. The hindquarters could be rounder, and shorter to show where the hip bones are.
I've never been great with front-facing legs, but cats have slightly thicker, short forearms, usually. There might not be as deep a dip from shoulder to neck, and the most noticeable joint from the front of the leg would be the wrist curving slightly sloping outwards, thickening before becoming the paw.
The ears could be less rounded, though of course it depends on the breed or OC you were drawing. Cat ears are most often triangular, and I would set them a little higher up on the head while lengthening the cheeks. Cats have slightly round heads.
I would make the tail tuft thick and blend it into the tail more, rather than a separate piece of fur, but that one is more a personal preference.
I would love to draw little bits to visually represent my advice, but my tablet's too scratched up to pick up my pen, apparently. '-_- If I get it working again soon, I'll add some pics.
Winter 
Night 
Sleet Moon: 
