This movie is far worse than "Plan 9." During long stretches it is boring, something I cannot say about Ed Wood's masterpiece.
However, to the question at hand. The footage you recognized was lifted straight out of
Starcrash (one of my favorite cheese films).
What got me was how, at the end, all the villagers that inhabit Earth welcomed the two refugees with open arms. The last interaction the two groups had involved laser fire and a lot of people running and screaming! I'll bet the villagers' were secretly thinking "Okay, be nice to them, get their guard down, then hit them in the head with rocks!"
Want to be really afraid? This movie is sitting right behind me, on my reference shelves.
Andrew