I never got the chance to see this in the theater in 1977, but it has been a staple in my movie watching diet ever since the original Super 8 release that same year.
I saw it in the theater... It was a game changer. Nothing like it had ever been seen before. Yes there were serials and Sci-fi movies but they were usually either extremely dry (2001 I'm looking at you) or campy hokey affairs. By all rights this should have been as well and a failure... but it wasn't! An interesting story world with a well thought out backstory, a lived in, dirty, and real place with characters with personalities and motivations... Who cares if there are fires and explosions in space?