You play through the 19 levels and get dipped in a fire..... right?
;-)
I'm talking about the replay length. e.g. when you spend the time doing stuff, rather than admiring the scenery going "..... buh? confused". The replay length is the length that I consider a game to be, mainly because you only play a game at the "i dont know whats going on" length, once. I'll play it at the replay length a lot more times, and thats what I consider to be more accurate on the length of a game.
e.g. if you have one game that takes like 10 hours to play through the first time around, but after youve sussed it out, it only takes half an hour to complete, I wouldn't say its a 10 hour game.
* - unless someones willing to go find one of the MIB deneuralizers so i can forget how to play portal and re-learn it