I have quit games almost minutes in and revisited later and found i was wrong. SO i tend to play at least several hours.. some games take for example FF 13, the tutorial levels where almost 20 hours before you had learned how to use all abilities.. (5-6 of those where cut scenes) pretty hard to judge it till you get into the game earnest (I wont say how good or bad it is then....) but a game like ARMA with is hyper realistic controls.. NO WAY.. i knew in the training, less then a few minutes in it was not a game for me.. (open a friggin door!!!!, maybe need keys for each foot when walking too!, real is good, but you have to decide on fun value and realistic at some point and say, who wants to open doors? in a fast action shooter))
it depends on the game.. if its not a control or interface issue, just boring r so-so game I try make sure I play in a little deeper to make sure I'm not missing something.