Video games and children

It's not like I have really big problems with Rep. Jeff Johnson's bill to try and prevent kids from buying violent and inappropriate video games by fining them $25. I don't think kids should be able to buy M- or AO-rated games, since they are clearly for adults. However, wouldn't it make more sense to fine the stores that sell them to the kids, much like we fine businesses that sell cigarettes or liquor to underage kids? I don't know what the point is of fining the buyers.

I really don't understand the constitutional issues here either. Restricting the sale of certain games to kids is no different from restricting movies in my eyes. Perhaps I am missing something.