Whichever IF framework you choose, you are likely to find that the better it is, the more it invites you to dream of alternate endings.
I would like to propose a discussion. Why not mine the plentiful narratives served up to us from Hollywood, and where they are lacking, explicitly branch to more interesting outcomes delivered by IF technology.
For example, this is an alt opinion on the character arc for Luke Skywalker.
If I had the time, resources, and mental capacity, I would love to create a piece of IF which delivered as a default experience the established narrative, yet allowed the curious to explore particular storylines.
It’s possible to do a “main run plus alternative histories” IF in pretty much any branching IF platform that can support a New Game+ mode*, although unless you are very careful and using lots of In Spite Of A Nail (where things gravitate back to the main plotline no matter how big a change is made), you will create a lot of work for yourself.
The first run would be a relatively linear run through the “default experience” and the subsequent runs would open up the alternative possibilities. A lot of visual novels do things that have the structure, but even those with routes that don’t share lots of written and visual materials with each other don’t necessarily go all-in on the sort of “theme and variation” approach that I think you have in mind.
That strikes me as a very good way to think about this sort of thing. The main run has to be where an author would spend the most time to get right. That’s the story by which most people will judge the work.
Those who come back for a second helping (or are tempted to stray from the signposted routes) might be more forgiving of rough spots so long as their curiousity for exploration is satisfied.
The Baker of Shireton is built as a time-management sim, but the player can break out of those parameters and learn more about the world by doing some weird and not-very-well-hinted activities.
The sequel The Cursèd Pickle of Shireton also has a main plot that the player has to discover in the midst of another game - essentially by breaking it, prompting one reviewer to ask “Does this game even have an ending?”
Transparent did this somewhat, but I didn’t clearly establish the player’s goals so it confused people. Ostensibly you were to take pictures of things in the mansion that were interesting and get paid for the photographs by leaving the property as the main game loop. If the player decided to investigate the weird things happening, they would be potentially drawn into one of 3-4 longer puzzle-chain endings.
I played a bit with rewarding multiple play-throughs in robotsexpartymurder: The game is pretty open and lets you do what you want to do, including not solve the entire plot but still reach a satisfactory game ending. To get the best ending, players have to do some strict time-management and hit plot details as soon as possible since some plot points take a couple days to resolve and the player can run out of time. There are certain plot points that can be accomplished much earlier in the story if the player brings in past knowledge from a previous play through.
If the player knows their neighbor’s name when they first meet, you can hang out immediately and obtain a very important item right off the bat.Using this item (and more specifically knowing how to use it) on the very first day is the only way to see the entire Em plot.
If the player knows how to specifically use that item already without being tutorialized by another character they usually meet on day 2, they can jump ahead and make the plot progress a lot faster and get the full ending. The game lampshades this is “Of course you know how these things work, you’re a smart person…”
The main slightly impolite plot point that is easily missed: The player must date Kim on day 2 when she is first available and report specific details to Olivia and Alex as soon as possible to have access to obtain the Macguffin in enough time to allow the player to access her storyline and the resolution of the murder.
My somewhat absurd idea for a game for a while has been making one that is thematically different depending upon your initial actions (which may not be apparent) at the start - a conventional Treasure Hunt, a Horror game, dealing with an attacking Dragon, uncovering a Conspiracy, and returning from dead. They all would be based on the same basic structure, but would have different results; the town you visit in the Treasure Hunt version is burnt down in the Dragon version.
One of the Zelda games did this very well. Simple chicken-chasing tasks moved you around the initial map. Then later on when bad things happened (Tower of Ganon, etc I think), the emotional impact of seeing those innocent environments under stress really hiked up the engagement for me.
That’s the very definition of a “time cave” choice narrative structure. Main disadvantage is you’re writing several different separate plots the player may not see or even be aware of at all.
It’s from a now-classic article that talks about various structures: this particular one is named after the first novel in the Choose Your Own Adventure series: Cave of Time by Edward Packer.