Forum:Approx how long does it take?

I just got my son COD Modern Warfare 2 yesteray. About 30 mins ago, I looked over and see credits rolling up the screen with him saying "Dad, I think I am done". I logged onto this site to check out how many campaigns there are and to check with him if he had actually seen each of the campaign mission listed. He did.

Is it possible for "a kid" to make it through all of the levels in about a day of playing (at "medium" level difficulty)???? Seems like we are missing something.

I understand there is a "Special Ops" mission....but if he completed all of the missions in all 3 acts, what does he do next?