I don't think there's an ideal length, per se, but I absolutely do not mind paying 50 bucks for a very well done 20 hour game. The "dollars = hours spent" ratio is retarded and the reason why all games are padded up the ass nowadays.
>>714772710 (OP)
Replay value matters more. If i can't start a second playthrough immediately after the first without getting bored then it's a shit game.
What do you even mean by singleplayer
Do you want to specify it to story-driven campaigns?
There are plenty of singleplayer games where the idea of trying to quantify their 'lengths' is nonsensical, they just don't work that way
>>714772710 (OP)
I'm more like 35-50 hours guy, if game is really good.
If it's like Baldur's Gate 3 or Pathfinder that turns into shit half way, then wish it ends asap.