"Mission Galactica: The Cylon Attack" was given a limited theatrical release in 1979, making it a sequel of sorts to the theatrical version of the series pilot. However, no explanation is given for the appearance of John Colicos as Baltar, who was killed off in the first film.
"Mission Galactica: The Cylon Attack" is comprised of three episodes of the television series, edited together into a two-hour film for theatrical release. The three episodes are "The Living Legend" (parts 1 & 2), and "Fire in Space".
One brief scene does not appear in the original television series, showing a pair of Cylon centurions walking down a corridor which appears to be the same set used for the Draconia in "Buck Rogers in the 25th Century" (1979).
A different sound effect is used for the Cylon raiders than is heard in the TV series.