If a game takes more then five minutes to become fun then return it. I've returned plenty of games with under five minutes of play time, because I don't have the patience to purchase boredom.
Two hours is far more than enough to determine if a game is for you.
There are entire genres where that makes no sense. It would be like returning a book because the first page didn't immediately grab you. Not everything should be designed for attention deficit teenagers.
Two hours is far more than enough to determine if a game is for you.