Don'tcha just yearn for those simpler days? Well...it overflows in this film: simple plot; simple effects; simpleton acting. Some preachy dialogue. Inferiority, typical of low-budget, 50s, b & w, sci-fi; concluding with a happy ray of hope, after a quintet decides to board a drilling capsule and escape contemporary threats (i. e., the nuclear bomb) by boring into inner space. Perhaps too much boring for a majority of viewers: the blandness will be overly-intense. By the way, it's a trio at movie's end, but not because of any ferocious animal-life: the most violent beasts here are rabbits. P. S...If the sun doesn't penetrate under ground, why was there any light down there? (So bright, in fact, that, in one place, there were shadows.) Only YOU can determine if it justifies any of your time and/or money to watch; but, in my opinion, it ain't worth much.
Review of Unknown World
