I've intended for years to write an article summarizing my thoughts on this genre; as I again lack a suitable book for reviewing for the month, I'll do so; more examples prove waiting was for the best.
The open world genre of video games is marked by providing a large world to explore, without much in the way of required direction. In preparing for this, I learned several older games I've played are considered members of the genre. I don't consider games from the last millenium, which I've played, to qualify; amongst other considerations, the scale afforded to them makes them extremely different.
An interesting characteristic I've noticed is, after beating such a game, I'm completely relieved of any desire to ever play the game again. In the case of one game, the world was split into separated areas accessible by map; unlike previous entries of the game, there was no level structuring in each area, meaning I couldn't easily play my favourite scenarios again without also playing the game back to that point. I beat the story in roughly fifteen hours, finished most of the game within the next twenty-five or thirty-five, and spent the next twenty or thirty hours agonizing over the few secrets and trials remaining. I often found myself playing as if I were looking over my shoulder the entire time, due to how the camera was being manipulated, unnaturally in search of the remaining goals. No desire to touch the game in any form again lives within me, perhaps entirely due to this exhaustion.
In the case of another game, in which I've yet to do everything and in which I've put more time, I'd realized most of the game was spent wandering aimlessly, or travelling from one end of the large map to the other. The story of this game suffered from being sliced into small pieces and split amongst many obscure regions of the world; the gameplay suffered from the fact that, while there were things to do, not too terribly many were worth doing. The game even mocks the player with how it awards he who bothers finding the hundreds of small secrets scattered about, which I only know from elsewhere. It speaks volumes that the only reason I'd continue to play that game is to finish the few remaining puzzle areas, and how the most fun I'd with the game was in the trial areas divorced from the world.
Most recently, I've finished a much shorter and more linear game, although this is still a game that features exploration and hunting for secrets. I've beaten this game in roughly ten hours, but there remain secrets and other things I've yet to uncover, and there is also a hard difficulty and beating the game more quickly to do now available to me; I don't believe the shorter length accounts for all of my wanting to play the game again, although it's worth mentioning the game has very little wasted time, in comparison. I believe it's more fun to play from start to finish than to wander aimlessly.
So while I can have fun playing an ``open world'' game, the exhaustion limits it to once a lifetime.