Well considering gaming and the general gameplay of a game, I would have to say that most games that anyone ever plays are very linear, in fact even some of the best games that have come out so far such as Call Of Duty Modern Warfare 2 and Batman Arkham Asylum are anything but free storylines... I don't think anyone can really say that they are bad games because they've pushed gaming quite far but it can be said that you can't choose what happens with the certain parameters within the gameplay. You don't choose the ending you just get to it, and to me that seems right, but I can't help but feel that I want more.
I suppose there is no such thing as unlimited gameplay, but the imagination can provide a huge scope as to how a game could be made. Do games developers stick to what they are doing and keep the gameplay the same? As in start middle end? Or do they try and mix it up a little and give it more freedom? Is it even possible to change the way gameplay is produced.
I suppose i'm being a bit one sided within this approach, there are certain games out there that can offer an almost unlimited gaming experience. Star wars The Knights of The Old Republic offered the player a long and immersive gaming experience but the best thing about it was that you could do whatever you wanted really, but this game like all others does have an ending and is still set to the basic plot line start-middle-end.
Gameplay is important and it does define how the game is played and how everything happens within a game, I think a game should be more of an experience than a short story, but it has to be gripping as well as long which would prove a large challenge to any games producer!!