LEGO Alien Conquest

LEGO Alien Conquest is a 2011 LEGO Science Fiction theme, and the immediate successor to LEGO Space Police. Throwing back to 1950s/1960s science fiction, it's about an Alien Invasion of Earth and the efforts of the Alien Defense Unit to repel the invasion. Compared to the other recent LEGO Space lines, it's much more lighthearted, goofy, and doesn't take itself at all seriously.

Tropes used in LEGO Alien Conquest include:

Alien Abduction: The sets even give you civilian minifigs who serve no purpose other than to be abducted!
Alien Invasion: Since tripods are used, this invasion seems similar to War of the Worlds, but with human technology over 100 years more advanced, to the point where humanity and the aliens seem equal.
Ascended Meme: The fighter craft accompanying the Earth Defense HQ set is a nod to the Vic Viper spacecraft style that is very popular in the AFOL building community. One of its stickers even pays tribute to the late Nate "nnenn" Nielson, the pioneer and undisputed king of the Vic Viper style.
Awesome Personnel Carrier: The Earth Defense HQ set. Most of the LEGO fandom agreed with the trope name.
Flat Character: There aren't even any distinct characters aside from the leader of the aliens, and even he is completely undefined beyond being the leader. As with many LEGO lines, the intent is to have every character be a generic member of their respective force, the better to both amass armies of identical minifigs and for children to characterize themselves and thus foster creativity.
Flying Saucer: Most of the larger alien craft; the one that isn't, the Tripod Invader, can still split off the legs to act as one.
George Lucas Throwback: To science-fiction movies of the 50s and 60s, with a strong emphasis on B-Movie clichés and tropes. It also contains elements throwing back to Classic LEGO Space, most prevalent in the bright blue colour scheme of the ADU forces.
LEGO Theme Busting: For what's ostensibly a LEGO Space theme, it was pretty much designed to fit in very well with LEGO City, given that it's about invading a modern city on Earth.
Home Guard: Given that "defence" is in their name, it's suggested that the ADU is this and they're not actively fighting in space or something.
Lighter and Softer
Little Green Men
The Mothership: The Alien Mothership, obviously.
People Jars: Both sides are guilty of this - the aliens are pretty much invading for the sole purpose of doing this to humans to power their ships, and the ADU in turn uses prison pods to capture aliens.
Puppeteer Parasite
- Shout-Out: They look more than a little bit like Futurama's brain slugs, as pictured in the Puppeteer Parasite trope page.
  - ADU as a whole, going by the mini-bios on the official site, seems to be this to X-COM, what with their being a gung-ho, semi-military force in blue battlesuits who hunt down UFOs and reverse-engineer alien technology to even the odds.
Space Marines: The ADU soldiers have this vibe, especially in terms of design.
Stealth Sequel: According to the LEGO magazine, 2012's LEGO Dino theme is a sequel to Alien Conquest: over-running us with dinosaurs is apparently plan two from outer space.
Tripod Terror: The Tripod Invader.