As an undergraduate student you won’t find a strong “focus” on gaming in any curriculum. You should make sure the school offers courses in graphics, animation, simulation, and similar computer science areas. Also, since art is a big part of game development, a school with a strong art program might also be good. It is in graduate school that your son will have a better opportunity to really focus his attention on game development.
That all being said, a lot of computer programmers want to get into game development. It is a field that seems fun and lucrative. It is very competitive and more importantly is not always positively received by those computer scientists in less “hyped” fields.
A good analogy is to say that if you advertise you found $10 on the road, every Tom, Dick, and Harry is going to show up on your doorstep saying that it is his. How do you know who is sincere? The attractiveness of game design has an effect in computer science similar to that $10 bill, so marketing your son’s interest in game development will not be easy because his willingness to actually commit to making serious academic contributions in the field will be inherently doubted. (In other words, pursue topics in computer science important to game development but don’t necessarily advertise his ultimate goal to admissions personnel.)