That's great! I'm sure some of the other people who have been animating longer can help with tweaking the movement, but the only thing I noticed was towards the end, when the tip of the tail flips towards the head, it looks like there's a kink in the tail a bit further up. Also, when the cat jumps, it might be better to see the feet in the frame as he lands. Nice work!
Lookin' good indeed.
Now that you've got the major animation done, are you planning to animates the eyes? The eyes looking down to where the cat is jumping would be a good idea, and perhaps squinting because of the effort it takes to jump. That would add a bit more realism.
As they say, "the eyes are the window to the soul."