Plot? Well, the title pretty much sums it up (I guess you could read some tolerance stuff in the subtext...but this isn't really a "subtext" kinda movie.) But that doesn't matter...Monsters Vs. Aliens is fast paced and beautifully rendered with enough slapstick and high-jinks to keep the kids happy and just enough jokes that will sail over the heads of the youngsters to keep the adults engaged (and stuff blows up...who doesn't like that? :-)
Keifer Sutherland is a hoot (and all but unrecognizable) voicing the the hard-bitten General W.R. Monger who has been keep the existence of monsters away from the public for 50 years, Stephen Colbert has a daffy turn as the clueless President, and Reese Witherspoon is at turns winsome, befuddled, and determined as Susan who is turned into a 50-foot woman ("Gigantica") after being exposed to a meteorite on her wedding day.
Hugh Laurie is grand as Dr. Cockroach, a mad scientist who turned himself into...well...a giant cockroach, Will Arnett is fine as the stalwart and prideful Missing Link, and Seth Rogen steals the show as the affable but brainless gelantious blob named Bob.
The movie wears its influences on its proverbial sleeve unabashedly...I saw winks to Star Wars, Men in Black, Independence Day, The Day the Earth Stood Still...and, of course, The Fly, Attack of the 50-Foot Woman, The Creature from the Black Lagoon, and The Blob... among others...but it does so with such charm, verve, cheekiness, and good nature that you just go with it.
In the vein of full disclosure I eschewed the 3-D version in favor of a regular 2-D showing...eyes as old as mine weren't meant to try to cope with 3-D for an hour and half...but I could see many of the shots that probably really popped in three dimensions.
Is this a great movie? Nah. But it's a heckuva lot of fun and what more do you want from a cartoon?