There is no gore in the traditional sense in this film. However, there are scenes which would be disturbing to young viewers because they show the deterioration and destruction of human-like (although not human) bodies.
There is a scene toward the middle of the film, for example, in which the characters are given faces (made out of clay, constructed over their robotic helmets) which make them look somewhat human. The faces are cartoonish and fake-looking, but it is quite jarring when the sun melts them, and frightening when the characters peel the masks off and discard them. This is mostly due to the scary music and lighting used in the scene.