Aluminum Christmas Trees: The "Atomic Laboratory" requested in one child's letter to Santa is actually a real thing. It refers to the Gilbert U-238 Atomic Energy Laboratory, a child's chemistry set which included a small sample of (mostly) depleted Uranium-238. Due to the potential for radiation poisoning (and even more so the extremely hefty price tag note It retailed for $49.50 in 1950, the equivalent of $488 in today's dollars), the lab was not a commercial success unlike Gilbert's other offerings and was on the market for only about a year in 1950-51. Still the sheer WTF-ery of the idea made it a popular meme up to today.
Esoteric Happy Ending: Sure, Lupita got her doll, but her dad still hasn't found work and her family is still dirt poor.
Fridge Horror: One child writes Santa Claus a letter asking for a little brother. Santa puts it in a box and says "here's one for you, Mr. Stork." Writing a letter to Santa can get your mom pregnant apparently.
Fridge Logic: Lupita's dad moans he hasn't found work. On Christmas Eve. At night.
Glurge: You know you've done something wrong when your adorable kids' movie ends up becoming the Trope Namer-by-proxy for Nightmare Fuel.
Harsher in Hindsight: The kids from India appear to be making rifles, which can be rather sobering after everything with the War on Terror near that region.
The montage of the children from all over the world writing letters to Santa, especially those who ask for additions to their family.
Followed up by, despite the post office dumping all of the letters to Santa into an incinerator, they are all magically transported to Santa directly where he reads Every. Single. One!
When Santa makes it possible for the Lonely Rich Kid to be able to see him as he is and the little boy immediately hugs him on sight. Plus, pretty much any moment Lupita is on the screen.
Lupita's reward for her faith in Christmas: a gigantic doll. Crow remarks it's not a doll, it's a sister, since the thing is as big as Lupita herself.
Moral Event Horizon: Pitch crosses it near the end at one of two points: When he taunts Lupita in her sleep about never having a doll because she didn't steal one, leaving her in tears when she wakes up and cries for her mother. Or when he intends to leave Santa stranded on earth so that he will die.
Paranoia Fuel: Santa has machines that can peep in on you and even listen to what you're saying, anywhere on Earth. He even has one that can see into your dreams.
Mike: (As the porthole for the Cosmic Telescope opens): Santa's tendrils reach far and wide, there is no hiding from the Klaus Organization.
The Scrappy: The narrator. He loves telling the audience the most obvious things and never shuts up.
So Bad, It's Good: What was supposed to be harmless fun to introduce Mexican kids to Santa ended up becoming the Trope Namer-by-proxy for Nightmare Fuel thanks to Mystery Science Theater 3000. The movie tells the story of a Human Alien Santa from Another Dimension battling demons through Slapstick and the help of Merlin and a supply of advanced surveillance equipment that would make the Illuminati hang their heads in shame. Still, the surrealness does give it a certain amount of charm. At the very least you won't be bored watching it, and you're unlikely to ever see anything quite the same as it ever again.
Combined with the moment of Heartwarming above as the kid not only hugs Santa, but clings to him and begs him not to leave and reassure him that someone cares about him.
Lupita's mother starts crying when Lupita asks why Santa never brought her a doll.
The Woobie: Lupita and the Rich Kid, for opposite reasons. One of them has nothing but the love of her family to get by, the other has everything he wants except love.
, a child's chemistry set which included a small sample of (mostly) depleted Uranium-238. Due to the potential for radiation poisoning (and even more so the extremely hefty price tag note ), the lab was not a commercial success unlike Gilbert's other offerings and was on the market for only about a year in 1950-51. Still the sheer WTF-ery of the idea made it a popular meme up to today.