Planet 51 is an animated film in which it takes the alien invasion concept to the other side... humans have stepped forth on an alien planet. On Planet 51, Lem is an average teenage boy, living his life when suddenly a spaceship lands and a human astronaut comes out, Chuck. Initially mistakenly thinking the planet was lifeless, Chuck gets a big shock. Although in some ways this planet is more advanced, the thinking is behind in other areas. It shares a lot of parallels with humans, and that is probably why it doesn't sit well sometimes. For one thing, Lem and his species speak the same language as the human Chuck. That said, there are more than a few scenes where the play on words is clever and funny. The plot is uninspired, you have your typical general who is convinced the alien is not friendly and is fixated on killing it, then there's a mad scientist who is completely wrong but too stubborn to change his ways. It can make for some boring scenes during the middle of the film. Planet 51 can surprise you with its directions sometimes, and not in a good way.