Planet 51

The main alien character is named Lem, and like some of the writing that Stanislaw Lem is best known for, this is comedic science fiction that shouldn't be taken too seriously. In broad outline, it is the kind of reversal that Lem might have written about, an alien planet like Earth that gets visited by an astronaut from Earth. However, Lem was also a very intellectual writer who included lots of minute detail in his fiction even when it was intended as humor, and this does not have that kind of detail. Instead, its detail is more like what you might expect from the Flintstones, which read more