Started a new outline. Covers the first 2 chapters. Another attempt to at least consider the scope of the game so that my efforts will actually be directed toward some sort of game coming out the other end at some point.
Each chapter has 8 quests, which seems about right. On a given playthrough, the player will likely be only doing a handful of them. It's hard to calculate, as there is not really a golden path (optimal way through the game). The player can do zero quests, sit in the corner, and it will progress. But there are important quests, if you want a decent story, you will want to at least attempt roughly 3-5 of the 8 I have outlined. At 5-10 minutes per quest, a conservative estimate for the two chapters is 45 minutes.
I'm aiming for 3 acts, although due to the nature of the story I can add on to that if I think it's reasonable to. So I currently have a ~3 hour game, although I have hopes that people will want to play through at least twice. I've seen plenty of people spend money for 2-3 hours of gameplay, but few are completely happy with that. And for something that at least looks like a traditional rpg I think reactions will be pretty poor. If it's free, maybe it fares a little better. If the core gameplay is actually interesting in any way!
I do expect Acts 2 and 3 to be a bit more dense than this first act though.
Edit: Oh and I just realized that my calculation in terms of quest time is quite underrepresenting overall time. There will be non quest-related time, intros and outros to the chapters, exploration, travel between areas when not on a quest, and time spent figuring out what to do next. So that's like the speedrun time :)
Another thing. This is just a first pass, and at a glance very few of the quests I've outlined have a significant timed component. Even worse, at almost no point are the quests running alongside each other, where doing one of them prevents doing the other. This may be something I am subconsciously doing intentionally, in easing the player into the timed element of Erik. On the other hand, I may just not be quite comfortable with that element yet. I'm definitely going to play with this outline quite a bit more before I set it in stone and start gearing my dev time to matching it.