Parents need to know that the cartoon Casper and other Casper movies are much milder than this one. There are deaths here and much talk about the spirit world and grieving the loss of parents. The main character, Kat, sees one parent as a ghost, and another parent dies and comes back with the help of an invention. Kat also has a crush on Casper, who died as a tween boy. Casper's ghost uncles can be crude and mischievous and they take Kat's father out drinking at a bar.
Violence & scariness:Much fighting, and three deaths of characters who are then shown as ghosts. Some characters willingly pass into the spirit world, thinking they can come back with the help of an invention.
Sexy stuff:Lots of innuendo, much of which will go over kids' heads -- as when Casper's mean uncles drop Dr. Harvey's pants, and one comments, "You're no Marky Mark."
There were some vulgar words, sexual inuendos, even 12 year olds dating was odd to me, and the issues with maternal death and being able to "come back" from ghost form could be confusing to a younster.
it starts out cute, but there's plenty of violence and bad language. towards the end of the movie, the villain screams out, "you b--ch!!" (referring to a female dog).