Ok, nice. The movement range probably does not match nature, but having anything non-rigid and controllable sounds quite good.
Twilight's body, as already mentioned by others, looks off. She's like a totem pole sticking out of the ground with hind legs attached to the sides.
To me, the swords seem short. But more importantly, they can't look action-y if they aren't performing any useful action. The ponies aren't trying to hit each other, or even push away the other's sword to have a clear shot at the opponent. Trixie's sword is swinging up into nothingness, Twilight's is swinging down into the ground. If one of them is blocking, then at least the other's sword should be moving in a threatening direction.