I was really exited when I read the title, there are far to films with bizarre space themed hybrids.

I think there are a few things that you could do to really make your next film better: First I would try to build some sets, in this film there was nothing that really established the setting in space.  Even adding something like a small spaceship on a landing platform in the back would have helped set the tone.  You may have been able to improve your backdrop by punching some pin holes in it and aiming a lamp from behind to create some stars.

Later in the film I was a bit confused after the first two pirates were killed, where did the other figs come from, there was not much continuity if you had taken a little time to establish that they were with the space pirates it would have helped.  Good luck!