Peter Jackson surprised attendees at New York Comic-Con by showing the first 24 minutes of "Mortal Engines," an epic fantasy film in which giant mobile cities crush smaller, weaker towns.

Deadline described the footage as  "a widely original concept that played exceptionally well to the crowd at Madison Square Garden," while noting that the venue was "only half-full."

According to Gamespot, the movie feels like "a classic fantasy/sci-fi adventure film from the '80s. The mobile towns and cities and overall feeling of this world are reminiscent of something Terry Gilliam would have come up with [in] "Time Bandits."

Based on the first of four steampunk novels by Philip Reeve, the film stars Hera Hilmar ("Da Vinci's Demons") as scarred assassin Hester Shaw and Robert Sheehan as Tom Natsworthy, an apprentice historian who joins the resistance. They're trying to defeat villain Thaddeus Valentine (Hugo Weaving), who was responsible for the death of Hester's mother.

Andy Serkis moderated a panel with cast and crew, calling the movie "another extraordinary exercise in world-building."

Jackson (who is producing, but not directing the movie) said that the film is not technically set in a post-apocalyptic world. "The story is set 3,000 years from now. So it’s post-post-apocalyptic."

In this desolate future, war has "cracked the surface of the world. Volcanoes burst out. The war redefines the surface of the world," Jackson explained. There are no countries or borders any more, just "cities [that] rise from the rubble and end up on wheels chasing each other."

We also have a new trailer and new character posters for the movie, including South Korea-born singer-songwriter Jihae as Anna Fang, "a dangerous outlaw with a bounty on her head." (Yesterday, Universal released a featurette introducing her badass character.)

"Mortal Engines" opens December 6, 2018, according to Universal's Twitter, but December 14 according to their YouTube account.