Look, games are getting longer these days. Some games let you save at any time, some do not. Some have frequent checkpoints that you can use to resume the game when you come back to it, some handle this much less gracefully. Even Arcade games like Commanders: Attack of the Genos now have levels that can last 30-45 minutes.
On the other side of the coin, gamers have less and less time these days. They have jobs, families, responsibilities. The casual folks are looking for bite-sized game experiences, and even the hardcore sometimes just have to go do something else. You know, to an event with the spouse, to feed the kids, to run out when somebody calls. Life sometimes cuts in, and in a lot of cases the next save location or checkpoint is just too far away.
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