The actual movements need to be a lot smoother, and there was a lot of noticeable camera shake, but doing zero-g is very ambitious. I wouldn't expect pretty much anyone on this site to do it perfectly. I did an entirely greenscreened one a few months back, but I left the movements being too quick, and also you're trying to achieve a slightly different effect (yours is zero-g grappling, mine was floating).
So for the future: watch out for camera shake, and smoother movements. Astronauts normally move really slowly in space, right? so you have to be even smoother than when shooting a normal gravity brickfilm.
Hope this isn't too rambly and is helpful.
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