I’ve only recently noticed this: when starting a new game i usually look it up on howlongtobeat.com first and check the average completion time. Especially if it’s an indie game, cos it’s hard to tell if something like that will last two hours or twenty hours. You can kinda tell from the price sometimes but not always.
This is partly to decide whether or not I’m gonna try and complete it in one sitting - I don’t want that annoying situation of coming back for a second sesh only to discover I was five minutes away from the finish line (as recently happened with Gorogoa). But aside from that, I just like to have a rough idea of how long it’s going to take.
Some games give you this information in an indirect way by having a list of levels or whatever, but a lot of games just carry on until they end and that’s that. Sometimes you’re able to infer from the story and/or pacing, but that’s a tricky situation too - something like Half-Life 2 will provide you with an ultimate goal, but then throw constant obstacles and detours in your path, so it’s never really clear how far away you are from the end. Or with Zelda you’ll know how many Special Things you have to collect - but there’s probably another set after that. (I guess a newcomer might plausibly expect OoT to end after the third spiritual stone?)
Is it an important element of game design to give the player a rough sense of how far through they are? Or do you not really care?