This isn''t, as far as I can tell, a design forum that specifically caters for commercial games. So the people talking about a game that''s too short need to break that habit and consider that not every game has to be an artificially padded 50 hour tale of growing from a generic shit-shoveller to a generic world saving hero. In some cases extending the lifespan of a game because it''s ''what you do'' just destroys the good idea at the heart of it.
Unfortunately, the only viable place where these unsullied ideas can currently exist is in the interactive fiction community, because there''s no overhead for building a game engine to your specification. If you want make a game based around one great idea, you can do it, because it''s not going to take you a year to get a basic engine up and running.
Mods for popular games are a good alternative, but in many cases a barrier is hit as soon as you try to do something that doesn''t involve blowing something else up.
"Don''t take me for an ordinary man. Although I am an ordinary man."