I think 15-20 hours is the sweet spot for me. Otherwise I might end up dropping it before hitting credits.

Note: The above rule doesn't apply for fighting games, jrpgs, and monster hunter.

A bit of a non-answer, but I'd say "as long as it is enjoyable".

For example, Muramasa Rebirth and LiEat both are rather grindy in their own scopes, but the latter still manages to be short enough it doesn't overstays its welcome.

Or on another example, Solatorobo could easily have ended at the villain's defeat, but the events afterwards still build up on that world's lore, and so making the extra playtime worth it.

And then there's sandbox games like Minecraft and Starbound, which are literally as long as the person is enjoying them.

I guess it will mostly depend on people's age, having children for instance quite reduces how much time you can spend gaming

i think the "playtime = value for money" mindset is actively harming the industry by making it about quantity rather than quality. a game should be as long as it needs to, and that's not correlated with price. some of the best experiences i've had has been with €10 10 minute games, and some of the worst has been with things that just outstay their welcome in order to meet an arbitrary target. it's the blockbuster mentality, except blockbuster has been dead for a while.

It depends. When does the game run out of content?

Like if you make a game of say 3 hours but someone says "the game should have 10 hours of playtime" so you just add in 7 hours of worthless stuff then optimal time of the game is 3 hours.

A classic example of this is "open world rpgs". Yeah the story is 5 hours but if you climb all towers, which are 1 of 3 templates of which there are 200 towers , and defeat all the bases, which are 1 of 4 templates of which there are 300 bases and ride a horse across the equivalent of 500 Sq acres of small empty barren hills, the game takes 150 hours... Take the money for all that development time and make the story better.

I'm guessing you mean playtime to complete? For me, 50-80 hours is ideal. I like to think in terms of getting an hour per dollar. So anything beyond 80 is gravy. And I do have quite a few games where I've passed that up, a couple even hitting 1000+. Anyways, if a game is only like, 20-25 hours but I paid $60-70 for it, I will 100% feel gipped and annoyed. Not that that has happened in forever because I will google playtime before buying any expensive game.

At least 1 hour for every €1 I paid for the game. I like if games have 8+ hours of unique gameplay (no grinding!) Most games I play 50-100 because of grinding. I have a few games over 2000h

Looks like I'm one of the odd ones.

The games I tend to play take way longer - sandbox like Dwarf Fortress, Satisfactory etc can last hundreds of hours, or rather I take longer because I'm bad, lol. Just played Hollow Knight for the first time - took me 150 hours and not even got full percentage! Wish there was even more content in it.

As I get older, I find anything over 40 hours starts to give diminishing returns. And under 30 hours is usually preferred.

Some of my favorite games were ones that I finished in less than 10 hours. I think 20-30 hours might be best. 50+ hours for a single playthrough I think would be too much, unless I'm still having fun.

I usually enjoy at a maximum 50-60 hours. It does depend a lot on what the game is offering, though. I get distracted and play games in hyperfixations, so if a game can't keep my attention I will absolutely move on without finishing it.

As others said, 20-30 hours is best, around the same time an average book takes to be read.

I believe it is not possible (or very hard) to go beyond 50 hours without putting in cyclic gameplay, which is a bit cheating. Towers and all are fine, but games tend to abuse theses mecanics to make a game unfinishable in less than 100-150 hours.

Under 10 hours to complete the game, like an experience is perfect for me. Not everyone has a lot of time to play games. If the game is good, i have a nice time and can replay it, if it's meh, i can satisfy my curiosity by finishing it and move on something else. Indie games best capture theses.

Again, there are exceptions. I've been playing The Legend of Zelda Breath of The Wild for more than 200 hours with my family and I still enjoy it. Same for Minecraft, i guess.

15 hours is my limit.

This is one of the reasons I hated Death Stranding. At 40~50 hours for the main campaign alone, the fun per minute ratio is greatly diminished.

I'd rather play a replayable 15-hour-or-less game: The Wonderful 101's campaign is 12~15 hours, but I have close to 100 hours in the game and the fun per minute ratio is much higher than DS.

I also don't predict I'll stop revisiting The Wonderful 101 any time soon; whereas, I have no intention to touch Death Stranding again past the 100%.

Another example: it takes 30 minutes to 1CC Crimzon Clover, and I've had more fun in the ~25 hours I spent playing this game so far than all of my time in Death Stranding. Every second is fun, no filler. I love that.

I mostly play games with infinite replayability. Roguelikes, simulations, ones with strong mod suites and community-cteated content. There's only three games I've played from beginning to end recently: Fez, Witness, and Stranded Sails.

A full winning game of Nethack takes ~3.5 hrs

Been playing almost daily for decades

Won like 5 times