Galaxy of Terror, Roger Corman, 1981.
Interesting cast, Sid Haig, not playing a villain. Erin Moran with two years of Happy Days to go. Robert Englund just before slasher film success. Ray Walston, who ST fans will know as Boothby.
James Cameron, future king of the world, did some matte paintings.
I won't ruin it as it's a bad film worth seeing. Not hilariously bad, but unintentionally funny in parts.
But for a couple of elements it could've been a decent low budget b movie Alien ripoff.
Feels like a movie that had scenes removed that contained important exposition. I was constantly confused about how did they get here, who is this now, where'd he get that from?
Edited to add, it's not for kids. There's an infamous scene where a giant slime alien attacks, strips naked, and rapes a woman.
According to the original script there was MORE thrusting and the woman is shown enjoying it.