From Wikipedia

The Lego Movie shouldn’t work. The build it yourself toy is not really a product that cries for a movie version; it is the least necessary movie adaptation to come out of Hollywood, trumping even Battleship. Yet somehow, The Lego Movie manages to be pretty gosh darn entertaining. It fails to find any emotional center, but it is funny and brisk enough to make up for it.
The movie stars the completely average lego man Emmett, who after falling down a hole at the construction site where he works is assumed to be the “special,” a master builder prophesied to save Lego World from the evil President Lord Business. He is joined by the mysterious pink and blue haired Wyldstyle and the wise-ish sage Vitruvius as they try to thwart Lord Business’ plan to glue all the bricks of Lego World in place on Taco Tuesday. Eventually they are joined by a handful of Lego heroes, such as Batman and Benny the Astronaut. While Emmett is apparently the “special” his defining feature is being as average and nondescript as possible. He has bought wholeheartedly into President Business’s conformist propaganda and seems incapable of the original thought necessary to build anything. Being a children’s movie, the usual sort of lessons are learned, lessons about teamwork and being yourself. Aside from a brief flirtation with a concept somewhat interesting and original near the end, a something that also manages to kill all the narrative momentum, it plays out pretty much how one would expect.

While The Lego Movie isn’t groundbreaking, it is smart and well made. Its humor manages to amuse both kids and adults. Its throwing references upon references to all the various media franchises that have been turned into Lego tends to be the weakest part. Sometimes it works, mostly when the appearance is actually integrated into the movie. Batman plays a significant role as part of the good guys team. When they show up for a quick joke, like the brief appearance of some Star Wars characters, it jars the viewer out of the movie. Mostly, it is just characters acting silly, like the spirit of a deceased character making “spooky” ghost noises when he returns to impart some important information on Emmet. It never manages to rise above being very good, but it rarely falls much below that.
The best part of the film is how the whole world is constructed out of Lego. When Emmett showers, the water is clear Lego bricks. When something is on fire, it is Lego fire. The movie really sells it with a charming stop-motion aesthetic. While it never feels like a commercial for the toys, it acts perfectly as one. It is hard to watch this movie and not want to at least dig out the Lego you had as a kid and build something. The look probably goes the furthest in sparking that desire.

While I am still not convinced of the necessity of a Lego movie, The Lego Movie is better than anyone should have expected. Like playing with Lego, it is sometimes messy and cobbled together but is simply plain old fun.