In Issue 9 (October 1977) of Starlog there was an article about the invasion of Sci-fi films touched off by the release of Star Wars. The article mentions quite a few movies and TV shows, some made it, some didn’t. All release dates are for the US.
A sequel to Star Wars – Empire Strikes Back (May 1980)
When World Collide – As I discussed in this article a number of writers and directors were attached to this over the years but it never materialized.
H.G. Wells’ In the Days of the Comet – Never made
The Return of the Time Machine – Never made
Return From Witch Mountain – Released March 1978
The Cat From Outer Space – Released June 1978
Space Probe – Released December 1979 as The Black Hole
The Thing From Another World – Released in June 1982 as The Thing
Buck Rogers TV Series – Premiered September 1979
Comedy remake of The Incredible Shrinking Man – Although this didn’t get made, it might have become the 1981 comedy The Incredible Shrinking Woman.
The Predictor – Not made
Childhood’s End – A couple attempts were made to bring the Arthur C. Clarke classic to the screen, but it still hasn’t happened.
Magna I – I did find a mention of this, with the full title Magna I – Beyond the Barrier Reef, in the May 30th, 1974 issue of The Wilmington Star News but it appears this was never made.
Meteor – Released October 1979
Timescape – Not Made. You can read more about this one in my blog post about it.
Capricorn One – Released June 1978
The Late Great Plant Earth – Released January 1979
Spawn Of the Slithis – Released July 1978
Alien Encounter – Released October 1977 as Starship Invasions in the US.
Gift From a Red Planet – Released May 1978 as The Alpha Incident in the US.
The Incredible Adventure - Unknown
Rocket Ship X Flies Again - Unknown
Skywatch - Unknown