This is a fun movie and I think you should go see it, but don't expect a masterpiece.
Pros- A light and effervescent movie that doesn't dwell too long on the dumber aspects and keeps moving from new and interesting location to new and interesting location with fun characters who have chemistry.
Cons- It suffers from plot-contrivance disease, a big dumb superweapon, and a token plot.
Suspend you disbelief enough to allow for a mish-mash of London landmarks on wheels that eats smaller mobile cities and you can get immersed in a fascinating new world with fun characters and novel set pieces.
This movie is a nonsensical romp through a fantasy alternate future earth. The fantasy elements here are fun and imaginative rather than tired tropes (with the exception of the plot which we will get into later) and are no less nonsensical than orcs/elves/dwarves/superman. The world of the movie is the real star here full of interesting details, locations, and differing tones. Each new area has its own feel, interesting mobile cities, politics, and a wealth of fascinating costumes (a suit-jacket made of buttons is a standout). I left the theater inspired and enthused to see the rest of the world (and the other mobile cities hinted at) always imagining what the rest of this universe looks like and the fun characters that must inhabit it.
The movie suffers from a rather dumb plot however, not overly stupid, and it moves fast enough that you don't dwell too long on the plot holes and contrived/played-out bad-guy-with-superweapon-that-we-have-seen-many-times. The big bad and the protagonists aren't overly well developed either but they get moments to shine, a twist or two, and movie doesn't sit still long enough for their relative flatness to be boring so they remain light and fun. The last plot criticism is the utterly boring "final big battle" which is much less interesting than the "mobile city" fights that the movie starts with. There is good bit of rather subversive subtext involving "municipal darwinism" and geopolitical east-west tension (that makes you think about the current state of our world) that does elevate the plot somewhat. There is also a robotic minor villain whose plot resolves in an interesting way so that's nice.
Don't see this movie if you want a "plot heavy" movie with character-driven melodrama. Its a fun action-fantasy-romp of characters and locations in the vein of an Avengers movie with a similar level of dumb.
I was enthused about the world I entered and want to see more (with a more interesting plot next time) but due to the poor performance so far I don't think that will happen. Too bad!