Not really .. do not be afraid ... although why would you? This is a kids movie. It does have some nightmarish scenes, but overall it is a family movie. Watch it with your kids if you think they might be too scared of some imagery that they have to deal with.
Overall this is not a Pixar movie, it makes less sense than ... well I reckon there are many other movies that don't make sense. How can the Aliens be so knowledgable of earth, yet know so little when it is convenient? Because comedy and humor, that's why. Don't mind those things and just go with the flow and you'll have fun. Even if it is predictable to the point where you can guess anything happening in this ... that's why I said watch it with your kids too ... they are probably not as savvy as that ... or maybe they are but they don't care.
Overall this is not a Pixar movie, it makes less sense than ... well I reckon there are many other movies that don't make sense. How can the Aliens be so knowledgable of earth, yet know so little when it is convenient? Because comedy and humor, that's why. Don't mind those things and just go with the flow and you'll have fun. Even if it is predictable to the point where you can guess anything happening in this ... that's why I said watch it with your kids too ... they are probably not as savvy as that ... or maybe they are but they don't care.