Is it fair to judge a kids movie on its appeal to adults? On the other hand, with all the good animated movies that came out recently which also appeal to adults/parents and have quality that can be reviewed by "older" people to a better degree, I'd say all is fair. So consider this when seeing the rating and make up your mind, if it's important or what's important in its appeal.
Having said that, there is also the very real thing of having "star" names of German comedy or cinema taking on major roles here. People have made the argument, that there are professional animation dubbers, who know their job. Depending on your liking or disliking for that matter, someone like Schweighöfer will get a reaction from you. Again, as a kid you won't care, but probably also not read this. So it's the parents who if the kids want something new and you want something that they can watch by themselves, there are worse choices than this
Having said that, there is also the very real thing of having "star" names of German comedy or cinema taking on major roles here. People have made the argument, that there are professional animation dubbers, who know their job. Depending on your liking or disliking for that matter, someone like Schweighöfer will get a reaction from you. Again, as a kid you won't care, but probably also not read this. So it's the parents who if the kids want something new and you want something that they can watch by themselves, there are worse choices than this