An alien rift opens up in the pacific ocean and giant monsters start pouring out. After failing to stop them with our usual tanks and planes, the world unites to make giant mech robots punch the monsters to death. Because the robots are so big and complex, controlling them alone is too intense for a single human brain to comprehend. So mech robots are piloted by two crew members who mind meld with each other to share the power load. The better in-synch the pilots are with each other, the better the robots perform. The movie follows the events as monster outbreaks increase and a last ditch effort to close the portal is put into motion.
There is a LOT to get through in the movie in terms of world building. Sometimes so much so that you don't get a chance to absorb it all in. Likewise, since there's so much going on the characters don't get very developed either. Outside the 3 main characters, the rest of the characters are simplified stereotypes. There's the Russians. The asian martial artists. The bickering scientists who are too stubborn to appreciate each other's work. The drug dealer harvesting monster organs for the black market. The temperamental rookie and the stoic vet who also happen to be father and son. Etc.
Everything else is fantastic. The action is amazing. The cinematography always gives you a clear idea of what's going on while still keeping you in the heat of the action. The special effects are awesome. And even as thinly sketched and generic the other characters are, you can tell they're all having a lot of fun in their roles and they're genuinely entertaining to watch. It borderlines on campy but never quite dives off the deep end and goes full blown stupid the way some other action films (like The Mummy franchise) do. This is definitely the American Godzilla movie we never got.
I think during the scene where the giant mech robot was using an oil tanker ship as a sword is what made me just throw up my hands and go "fuck it, this is just awesome!" Every time you go "that was an awesome fight scene" it just keeps building up the next and the next and the next. I saw it in IMAX 3-D and while I could tell that it was post-converted in some places, the 3D did help to give everything a sense of scale and power. Several times during the film I heard the audience "ooh" and "aah" as monsters were torn apart and punched. This is a very... visceral film.
See it. Seriously, just go see it. It's a damn entertaining movie and I haven't been this energized for an action film in ages. Sure, it does have a few problems, mostly in the character department, but it's still leaps and bounds above other action films that we remember as cult classics today so... don't let that stop you.
Think of it like a Jackie Chan film. You don't go see a Jackie Chan film for his brilliant acting and character portrayal. You see a Jackie Chan film to see him perform insane stunts and kick ass. Likewise here, you KNOW going in that you're not seeing it for the character development or the plot. You're going in to see giant robots fighting sea monsters. And boy, does this film deliver!