Mortal Engines ★★½

“Mortal Engines” might not be a particularly good movie, but it’s a BIG one, and sometimes that can be even more important. Adapted (on steroids) from Philip Reeves’ neo-Victorian steampunk fantasy of the same name, this $100 million holiday-season event starts off like a supersized remake of “Fury Road,” as two mobile cities shoot massive harpoons at each other in a death race through the post-apocalyptic wastelands of Europe as Junkie XL’s bombastic score yowls in the background. Yes, mobile cities. One of them is London, and the other is a quaint mining colony that doesn’t have a name worth remembering; they travel on giant turrets, stretch a mile into the sky, and mulch each other for fuel.

This — viewers are informed via opening narration that sounds like it’s being read by Immortan Joe himself — is the way things have been since a scary fusion weapon of some kind wiped out the “ancient world” of the 21st century more than 1,000 years ago, decimating our civilization in a war that only lasted for 60 seconds. Imagine if Manhattan were mounted on wheels and then rolled across the Hudson river to attack Hoboken; it would look absurd, and be difficult to see clearly, but there’s no doubt that it would be worth watching on IMAX.