These five books have not just influenced video games with their ideas and themes, but they’ve also been inspired by concepts popularised in games.

Video games can get very long -- often frustratingly so - with some modern triple-A games spanning hundreds of hours. Not every game has to be huge, though, and plenty of indie developers have stepped up to provide shorter experiences that are just as polished and just as enjoyable as their high-budget contemporaries.

Some games can be beaten in a day or a weekend, but others will take literal months of time to complete. Here are the longest video games of all time to beat.