In my opinion, a game should be long, as long as it''s not pointlessly "stretched" with stupidities. These can be repetition (like in an RPG having to fight identical fights 1000 times or going through any maze in any game at all), not being able to save where you want or the game being overly difficult in a stupid way, forcing the player to load over and over again or not being able to skip any cutscenes (FF7 is a bad example of this, and I''ve heard FF8 is even worse).
Hmm... I don''t agree with original topic at all ! It''s even better that you get bored for game than that game is over too fast ! Only reason why I don''t buy games like Rainbow 6 and Hidden&Dangerous, is that I have borrowed both games, and played trough in 3 - 5 days (Rainbow 6 took longer)... and Just thinking that I would have payed 40-50$ for game this short... TERRIBLE. Adventure Games (I mean those old fashion) were excating, good, and long games, that took about week to play, and even if it didn''t give you any replay value, it was something much better than three movies
Unreal Tournament is again good example: It would have been so much better game if it would had way more singleplayer (heheee !) missions, but now I just use it to practise some times, and basically got bored to whole game... Too bad that I don''t have good connection to play on the internet.
When people buy games, they know if it''s going to be long or not or be repetitive or not. I think if everyone just bought the length of game that suited them, then there wouldn''t even be an issue here.