But as the latest add-on to Grand Theft Auto IV, The Ballad of Gay Tony, confirms the idea that games have a fixed ending may be coming redundant.
Post-nuclear war epic Fallout 3 is another example. Out of the box its vision of a radiation-ridden Washington D.C. is already huge but now there are three expansions to download that push the boundaries of the game back even further.
The latest, Broken Steel, even rewrites the ending of the game so that in Fallout 3 the end is, well, no longer the end.
And as games follow music and film and become downloads rather than retail products this trend is only likely to accelerate.
But with more people spending their time and money on additional adventures for their favourite games, it’s likely they won’t be buying brand new releases. So if these add-ons become the norm we can expect a future where fewer big-budget games are released.
Given some of second-rate releases that hit the shelves that might be a good thing, but it’s also likely to make the companies behind big-budget games less daring in what they create. So should we be welcoming the prospect of never-ending games?