It wasn't fluid, Mana. There were certain scenes in it that looked cool - when they attack the monsters at the opposite person's side - that one scene was super cool and well animated. But the rest of the fights, the scene when they're running and jumping around and landing on the plane's surface, for example, just looked awkwardly done. If you wish to see instances of fluid animation in this anime, look no further than the OP - that's the kind of animation the fights deserve. And I can count a number of sequences where the CG monsters looked out-of-place CG as opposed to the usual CG-well-done-so-it-fits.
Which is why I said the episode dropped the ball with episode 3. But maybe I'm just being a little too nit-picky. Idk.