I like the textures, but the attack doesn't feel very... attacky. I really want to give you amazing advice, but I don't actually know much about animation, so it's hard to say anything more than "make the movement more xtreme lol". I think you definitely need some kind of follow-through to the attack, though. I'm not really sure why the cat's motion stops where it does.
Also, it feels like a very slow attack. I don't know if you've ever seen two cats fighting each other, but they don't move at that speed, I can tell you that much. There's also a lot of cat body language to take into account. When a cat is pissed off, their ears usually don't remain erect like they seem to be in this animation.
I think you might have made things hard for yourself by choosing a behind-the-protagonist viewpoint. Cats have very expressive body language, a lot of which is hard to depict from behind.
I'm kind of confused by how the perspective would work in the game, do you have any mock-ups yet that demonstrate it? Is the cat supposed to be walking forward? Right now it kind of looks like it's taking a step up a set of stairs.
Anyway, I wasn't trying to be so negative, just trying to be helpful. Please don't be offended by this comment!
Here is an earlier version of it in game. http://hkasoftware.com/fileserve/Felinity/CatAttackInGame.mov
I really appreciate the well thought out and detailed feedback.