As The Special, Emmet is part of a fraternity of Master Builders--rule-breakers who don't follow the Instructions, and are therefore only bound by their imagination. This group consists of licensed minifigures--including the likes of Batman, Superman, Wonder Woman, Gandalf, and Abraham Lincoln--as well as some characters created for the movie, such as Emmet's foil/love interest, Wildstyle (Elizabeth Banks) and the wizard Vitruvius (Morgan Freeman, who needs to get some sort of "Best Self-Parody" award).
Lord Business's conflict with the Master Builders centers around the fact that he has built a perfect set of theme Lego worlds where everything is placed just so, according to the Instructions. He wants to keep people from "messing with his stuff." He's going to unleash a frightening superweapon to ensure that nothing in the world ever deviates from the Instructions again.
The Lego Movie's story works on a lot of different levels--it comments on "chosen one" narratives, considers the nature of various styles of Lego play, and includes some nice pop-culture parodies. The movie's look is gorgeous and unique, with CGI simulating stop motion animation, so that all the pixels actually resemble real plastic interlocking bricks. There's also some very solid humor, particularly from Will Arnett's Lego Batman.
So it's smart, pretty, and funny, my kids loved it, and I had a good time. However, I found myself admiring the Lego Movie more than outright loving it. The directors, the team of Lord and Miller, walked a tightrope, creating a love note to free-form Lego play without denigrating the licensed playsets that are the Lego Group's lifeblood.
But the balancing act delivers mixed messages that I found distracting. The villain's called Lord Business, which appears to set up an anti-commercialism message. However, the film is pretty much 100 minutes of nonstop product placement for the Lego Group and its partners. Lord Business is opposed by duly licensed and cross-marketed representatives of some of the biggest companies in entertainment, including Warner Brothers and Disney. The upbeat, Oscar-nominated anthem "Everything is Awesome!" is meant as both a symbol of the soul-dulling conformity of Emmet's existence at the beginning of the movie and a catchy pop track viewers should download on iTunes and listen to over and over. Am I the only one who finds this weird?
Now, these concerns are likely to fly over the heads of the kids that are the film's target audience (they certainly flew over my kids' heads), and I did enjoy the movie, so it is highly recommended.