There is no doubt what this movie is: a movie you can leave your kids watching alone. Nothing they shouldn't see, and nothing you (parents) should see. If you like stories for young school-age children, watch it. But be warned: a thin, completely predictable story, average acting, director just working for his money. Kids like we saw in hundreds of movies, dog as we saw in thousands... A typical German kids' movie. A detective/crime story suitable for their age. If you've let them already watch action movies like Speed, Matrix or James Bond don't bother with this one, they'll give up after five minutes. But if they have childhood like they should, and are not contaminated by Japanese violent cartoons, they'll most likely spend exciting 70 minutes. And let you do whatever you want to.
I suggest, it should not be watching this movie. With one exception: if you are an extinct-species-type of parent and you want to be with them and make this a time your family spends together, forget what I've said. There is no movie so bad that you can't watch if you want to build your family relations.
