
First off, cats don't really have chests. They don't have a collarbone. This helps them fit into smaller spaces. So the neck just kind of connects/disappears behind the shoulders. There is fur and connecting skin to the shoulders that sort of make a cat chest, as well as the end of the center of the rib cage, which, in certain positions and angles, you might see on a cat. Mostly though, they just don't have one. Additionally, their necks are generally pretty short and thin.
Cat heads realistically do not have a dip between their foreheads and their muzzles, it's normally pretty smooth sloping, with maybe a bit of a difference in angle, but overall not that pronounced, however this can also be a stylistic choice (ex., Disney's The Lion King style), but anatomically correct wouldn't be jutting out much. Cat heads are sort of like triangles, not squares or circles. Their eyes should also be closer to the front of their head (though they can be stylized different, in a side profile would be a lot closer to the front of their head). Your cat ears are perfect!
The rest of the body has overall pretty good anatomy- the legs and their joints, etc, but might need to be proportioned a bit differently. The lower joints on the back legs are a bit shorter (and for balance I drew mine a bit back instead of forward), unless it's on a breed like an Oriental or Savannah, which have longer legs in general. Your body was also a bit long.
Other than that, looks great! Overall you had a great grasp on anatomy already, just with a bit of tweaking and proportioning, would look spot on :)
@Fat Unicorn- Wow! beautiful piece! I love all the texture and depth in the face, it looks real. The only thing I have to pick on about it is with all the depth in the face, the mane seems to be a bit lacking in. The texture is there just it all seems to be one flat plane of texture. This might also be because of the quality of the image, I'm not sure c: But overall, looks great! The eye, nose, and bunched up snarly skin are especially nice. Love it!