Forbidden Planet provides examples of:
- Alternate Character Interpretation: Did the tiger come after Altaira because she felt sexual desire, or had it in fact been sent after the captain to assassinate him?
- Ensemble Darkhorse: Robby, who went on to sci-fi fame.
- Retroactive Recognition: Yes, that is, in fact, a young Leslie Nielsen, in his most famous "serious" role (and only his second-ever movie appearance).
- Prop Recycling: Robby's prop ended up in several TV shows. As did the C57D, primarily on The Twilight Zone. However, from the late 1960s onward Robby's appearances were usually made by replicas, which weren't as heavy as the original.
- Science Marches On: Altair appears as a spherical, reddish star in the film when it was well known to be a whitish A7 subgiant. In the 1960s, astronomers found it to be egg-shaped due to its rapid rotation.
- The opening narration is actually fairly pessimistic about space exploration; it states mankind would not reach the Moon until the 2090s (over a century later than we actually did), and that reaching the rest of the solar system would be completed by the end of the 22nd century (we're still waiting on that one, but a lot of older sci-fi assumes we'll get there faster than that).
- Strangled by the Red String: Altaira goes from hating the Captain to deep, unbreakable love for him for no reason whatsoever.
- Tear Jerker:
- Jerry's death, horrific? Vey much so...
- Poor Doc Osgrow sacrificing himself to help everyone.
- When Morbius finally comes to accept that it's his id monster that's been killing people (and is about to kill his daughter).
- Morbius's death after banishing the id monster.
- Visual Effects of Awesome: The monster, when visible, remains unforgettable to this day.
- Try watching this film on a plasma, the backdrops are amazing!
The musical includes, in addition to the above:
- The Woobie: Cookie.