The FX are amazing. The electronic score (by Bebe and Louis Barron) and sound effects exist as one and is literally years ahead of its time.
It has themes and characters analogous to The Tempest (c.1610–11): the remote island is changed for a distant planet; Prospero the magician replaced by Morbius the philologist with parlour tricks that astound; the servile Caliban role filled by Robby the Robot, surely the second most iconic mechanical biped in early sci-fi, denied top spot by Maria from Lang's Metropolis (1927). The threat, because every good story needs an antagonist, isn't any old 50s go-to creature (so no giant ants or big-brained aliens with tin foil hats), it's a powerful entity rooted in themes found in Jungian philosophy. Beneath the sheen FP is sci-fi that has something real to say about the human condition.