The good news: the rogue asteroid Flora, slated to impact with and destroy Earth, is destroyed by spacemen Robert Horton and Richard Jaeckel. The bad news: a sudsy, greenish fluid from the asteroid has made its way back to space station Gamma 3 with the astronauts, and soon evolves into an rapidly multiplying army of monsters that discharge lethal electricity from their tentacles. Delirious joint production between MGM and Toei in Japan fairly crackles with the breathless dream-logic of pulp and comic book science fiction (appropriately enough, since the script was co-written by Bill Finger, the long-uncredited co-creator of Batman) and tightly paced, economical direction from inveterate iconoclast Kinji Fukusaku (“Battle Royale”). The pint-sized, squawking creatures are ludicrous – though diehard tokusatsu fans will probably see no difference between the Green Slime and any of the rubber-suited creatures in Toei’s TV sci-fi (“Kamen Rider,” “Johnny Sokko” and what eventually became the Power Rangers) – and the love triangle between Horton, Jaeckel and doctor Luciana Paluzzi (“Thunderball”) is drippy, but the Pop Art sets and costumes, mostly excellent model work and plentiful man-on-monster mayhem more than makes up for these minor quibbles. Near-perfect Saturday morning/Halloween night fare for vintage and newly-minted monster kids alike; the Warner Archives Collection Blu-ray is widescreen and free of extras, but repeat listens of the fuzztone freakout title song (“WILL YOU BELIEVE IT WHEN YOU’RE DEAD?!?”) is a bonus feature unto itself.