Tropes for this episode include:
- Accidental Astronaut: Donald, at the end of the episode, accidentally launches the Spear of Selene back into space - with him inside it.
- All There in the Script: The two Moonlanders whose names were never spoken are listed in the credits as Gibbous and Palus.
- Arson, Murder, and Jaywalking: Penumbra lists Della's "faults":Penumbra: A failure. A liar. She snores.
- She does it again when voicing her concerns to the General.
Penumbra: She's a liar! She's definitely up to something! AND SHE'S NEVER WASHED A DISH! - Artistic License – Physics: Della uses gold (which has a melting point at a little less than 2,000 F) to repair her spaceship. Re-entry into Earth's atmosphere can reach temperatures upwards of 3,000 F.
- Be Careful What You Wish For: From day one, Penumbra wants to kill Della under the suspicion that she is a threat to the Moon's people. She only realizes the true threat in Lunaris, who intends to lead their people into a war with Earthlings, after she had realized Della never intended any harm.
- Bittersweet Ending: On one hand, Della has finally returned to Earth and is about to reunite with her family. On the other, Donald is accidentally launched out to space, General Lunaris, who initially appeared nicer compared to Penumbra, is actually a two-faced bad guy plotting to invade the Earth, and Della is unaware of both.
- Blatant Lies: Penumbra realizes Della may have heard the no-so-flattering things she said about her.Della: Who are you talking about? Sorry to startle you.
Penumbra: Ah, we weren't talking about you. We were talking about another foul-beaked beast. [Beat] You don't know her. - Bloodless Carnage: Donald fights the zombies with a chainsaw. All it does is neatly cut them in half.
- The Bus Came Back: Storkules appears for the first time since he moved to Duckburg, and Zeus since "The Spear of Selene!"
- Call-Back: The broadcast from the end of "The Shadow War!" plays as Della first enters the ship.
- The Call Knows Where You Live: No matter how hard Donald tries to avoid getting involved with his family's adventures, it almost always force him into participating kicking and screaming.
- Caps Lock, Num Lock, Missiles Lock: The non-reversible emergency launch feature of the Spear of Selene is controlled by a single switch on the main control console, allowing Penumbra easy access when sending Della back to Earth.
- Continuity Nod: Two places that Della wants to visit with the boys when she returns to Earth are Mount Neverrest and the Pyramid of Toth-Ra.
- Cruel Twist Ending: Just as Donald and Della are about to be reunited, Donald launches himself into space.
- Double-Meaning Title: The title refers both to the Spear of Selene, which Della repairs using gold from Tranquility, and Penumbra's personal spear, which Penumbra snaps in half and Della later repairs as an act of friendship. Della even draws attention to the fact that they both have spears.
- Evil All Along: As hinted by Lunaris' last line in his debut episode, he was only helping Della to further his own goals. Turns out he wanted to take the Spear of Selene's designs to make his own warships, and make the other Lunarians think she was an invader so they'll join him.
- Fastball Special: Apparently, Storkules threw Donald at his father, Zeus, using the hammock as a slingshot.
- Fearless Fool: Huey and Webby really should have known better than to mess around with a videocassette that reanimates the dead.
- Foreshadowing:
- Lunaris discusses the Spear of Selene's design with Penumbra, drawing particular attention to the emergency launch switch. Towards the end of the episode, he uses this as part of his ploy to frame Della for betrayal.
- Della tells the Moonlanders about her encounter with a golden giant in El Dorado. The giant appears in the very next episode.
- The cruise the family booked for Donald is stated to last a month and not have any means of contact with the outside world. This is so that when Donald accidentally gets blasted into space, no one will even know he's missing for at least that time.
- Furry Reminder: The characters acknowledge Donald is molting or losing his feathers from his head. He's totally bald by the time they buy him a cruise ticket.
- Freeze-Frame Bonus: The brochure for Donald's cruise boasts "5,000 varieties of hammocks!!!", and promises to "melt away stress, not feathers!".
- Freudian Excuse: Lunaris's desire to invade Earth comes from how his father, who apparently saw early rockets and became so scared of it that he drove his people into hiding. Lunaris wants to prove that he isn't a coward like his father by leading an attack himself.
- Great Big Book of Everything: Huey's Junior Woodchuck Guidebook has an incantation to dispel a mass reanimation of zombies.
- Heel Realization: Penumbra has one when Lunaris declares an attack on Earth, finally realizing that Della wasn't the enemy like she assumed.
- Hope Spot: Donald sees a rocket land in the woods, and, knowing it must be Della, joyfully rushes to meet her. However, not only is his sister already gone, but Donald accidentally pushes a button while poking around, launching him to parts unknown.
- I Just Want to Be Normal: Donald is busy looking for a peaceful place to nap. Sadly, it keeps getting interrupted by his nephews having adventures, and ultimately him getting launched into space.
- Jerkass Ball: When Della finally finishes her rocket and says her fair-wells, Penumbra tries making everyone feel bad by asking her why she can't take them with her when she is convinced that Della thinks she is superior. All this does is inspire Della to do just that.
- Meaningful Name: Combined with
Genius Bonus. A particularly fat Moonlander is named "Gibbous", which is the term for the Moon phase when it's almost round. - Mercury's Wings: Dewey wears winged sandals belonging to Hermes, which triggers the wrath of Zeus.
- Missed Him by That Much: Donald notices the Spear of Selene landing and immediately rushes to the scene hoping to find his sister, but she has already left it to find Scrooge by the time he gets there. Then he accidentally starts the ship and shoots to space.
- My God, What Have I Done?: Penumbra, particularly after learning that Della did actually consider her a friend.
- Noodle Incident: How Dewey obtained Hermes's sandals and everything that happened with the magic king-maker goat.
- No, You: Zeus's response to Dewey telling him he stinks.
- Oblivious to Hatred: Despite Penumbra's open hostility to Della, Della still thinks they're friends. Ironically, Penumbra does eventually warm up to Della and is very unsettled by the general's plans.
- Offscreen Moment of Awesome: Whatever Scrooge, Louie and Donald got up too in the other dimension that the goat took them too.
- Our Zombies Are Different: Huey and Webby awaken some zombies by playing a cursed videotape, and the effect is reversed by reading a chant aloud. Unlike traditional portrayals of zombies, these ones are capable of running.
- Papa Wolf: Donald steps in every time the kids are in danger, even though he really just wants some rest!
- Pop-Cultural Osmosis Failure: Della compares her and Penumbra's living arrangement to The Odd Couple. Penumbra, naturally, has no idea what she's talking about.
- Put on a Bus: The family bought Donald a month vacation on a cruise. However, as he waited at the bus stop, Della's rocket landed nearby and he got himself trapped in it then launched into the heavens.
- Shout-Out: Donald butchers zombies with a chainsaw a la Ash Williams from Evil Dead. Said zombies were raised from the Necronomi-cassette, and banished by a (pun on the) magic words from Army of Darkness.
- Staged Shooting: General Lunaris shoots himself with his gun and makes it like it was Della who shot him to convince the Moonlanders to invade the Earth.
- Theme Naming: The Moonlanders all have names thematically related to the Moon. There's Lunaris (simply meaning "of the Moon"), Penumbra (the partial shadow Earth casts on the Moon), Gibbous (a phase of the lunar cycle when the Moon is almost full), Palus (a type of formation on the Moon's surface) and Zenith (the time of day when the Moon is highest on the sky).
- This Is Gonna Suck:
- Donald's reaction to seeing Storkules.
- Donald's reaction to seeing a talking goat that appeared out of nowhere inside the manor.
- Token Evil Teammate: Lunaris is revealed to be one for his people. He wants to attack the Earth simply to be feared instead of live in fear like his father did. Penumbra appears to think this is too extreme, while the other Moonlanders are explicitly not warriors and were otherwise friendly before Lunaris conned them.
- Wham Episode: Della finally takes off back to Earth in her rocket; General Lunaris shows his true colours and convinces the Moonlanders to invade Earth; Della makes it back to Earth but Donald just misses her and accidentally takes off in the Spear of Selene. And the episode ends with Della at the gates of the McDuck mansion.
- Wham Line: After insisting that "everything is fine" throughout the episode, Donald finally admits that "everything is NOT fine", causing his family to be concerned.
- Wounded Gazelle Gambit: Lunaris burns himself with his own blaster to make it look like Della attacked him.
- Yank the Dog's Chain: Donald's bad luck is taken to its most tragic extreme here; Just when Donald is finally allowed to be given a vacation, he sees the Spear of Selene land, he rushes there to see if Della is there, only for him to accidentally hit a button and launch himself into space.
- You Remind Me of X: According to Lunaris, Penumbra reminded Della of Donald. There's no reason given, but both characters having Hair-Trigger Temper may have something to do with it.
- Zombie Apocalypse: Huey and Webby trigger one by playing a cursed videotape. Luckily, Huey reciting a chant from the JW Guidebook sends the zombies back underground.
