In a comedy atmosphere, this movie centers around the life story of Alex, who after losing his job struggles against paying the rent money, after his roommate has spend the money of the rent in hockey, so the house owner fires them out, so he has to live with his grandmother and her strange housemates.
If you're a video game geek and/or a stoner, Grandma's Boy isn't a comedy -- it's a documentary. For everyone else, it's an interminably flat, one-joke movie with admittedly a couple of decent laughs.
Even if you aren't under the influence, you might find yourself chuckling at various points during the movie, if only in disbelief at some of the things the cast is asked to do.