With an amazingly low budget of anywhere from 200,000 to 500,000 dollars, of course they would come up with some gimmick to help cut corners. Enter cinemagic, a way to tint scenes of Mars a strong saturated red, thereby hiding the cheap budget by lessening details you would not see anyway. The rat-bat creature stalking the astronauts (well, more or less, given the budget), was a pretty good and effective design; enough so that Cloverfield‘s (2008) New York invading alien would have similar attributes. Carnivorous plants, a one-eyed amoeba (I always smile, because it makes me think of Zacherle the Cool Ghoul) , the rat-bat creature, and an unfriendly three-eyed Martian (just pops up now and then), provide the action as cinemagic does its best to provide the red colorization (though the process was more involved because it used solarization).
Here is the pressbook. It focuses on poster art to sell the movie as well as TV and radio ads. And, of course, it touts the CineMagic gimmick.
You don’t need to travel to Mars to see more pressbooks from Zombos’ Closet.
ComicRack reader version: Download Angry Red Planet Pressbook