first of all, for a critique film, bag the special effects. If it's possible, show yourself doing several gaits and several transitions.
From what you have shown, which is almost only solid trotting, I can say "not bad!"
You are pretty solid and post nicely. You would be best to roll your pelvis a bit more under you (tipping the pubic bone more forward, less downward onto the saddle) . You have too much roll in yoiur lower back. Your left leg is really solid , but the right is a wee bit more forward and rolled out overly much. Minor things.
I think you have a lot of potential and the horse seems a pretty good match. At the brief canter shot, it looked like you got caught be surprise and kind of shut him down all of a sudden, but not totally sure on that because it was such a brief shot.