Hm, I personally didn't like the character design but maybe it's just me. I really didn't like the hair and facemask.
Everything flowed amazingly well and the action was good too. What I really loved was the scenery. It really felt like the inside of an advanced city.
And if he could cut off the tail and leg that easily, it should have been no problem to finish it with his sword, no? Well, where's the fun in that I guess haha.
I also don't know about a full movie. I'd like to see how they would incorporate the dialogue and whatnot. Good watch though