Wow, this is definitely an awesome addition to my favourites list.
You did well with the colour blending- green eyes on a silver body, yellow eyes on red, that was something I noticed. I liked their eyes in particular, you drew them really well, so kudos sir.
I really, really loved the music. It reminded me just a little of Lugia's Song from Pokemon the Movie 2000 (don't ask how I can remember what it sounds like), that suprised me a little, but it was a really good choice. Gave it the perfect atmosphere, peaceful but streamlined at the same time. My compliments to your excellent choice regarding that.
I loved the tails and their eyes especially. All animation was smooth- I can only imagine how difficult it would be to animate a cat with four legs and a tail. Rather akward, but you succeeded brilliantly.
The fight scene made me crack up, it was just so brilliant. The training made it look like it was going to be so awesome. The training itself made me laugh a lot, that was genius, and the silver cat just seemed the most agile warrior in the world. The whole fight was them scratching eachother and tumbling around inside dustball lol. Brilliance, it really was. That cranked the humour up to 9. Alot of the time they were pretty much identical, just different colours, but that's all right, you did amazing.
Not much of a plot, not much of a message, but so, so totally awesome nonetheless. Very well done.
~VelvetDarkRocks~