Complicating matters is that a creepy lost child hunter (Will Seltzer) has been sent after them, though amusingly Haley accuses him of being a child molester to get them out of one jam. Jimmy and Corey's father Sam (Beau Bridges) and big half-brother Nick (Christian Slater) are also after them...
So, a fun children's adventure in some ways, and a feature length Nintendo advert. However, the film does include a number of adult themes and in reality the kids would have probably ended up dead (or worse). But if you just enjoy the fantasy for what it is then it's a very enjoyable film.