I definitely advise listening to Ogre. He has lots of experience when it comes to struggles with finishing. ^_^
Here are a few possible methods you could use:
1. False choices
This is kind of similar to what Ogre mentioned, but in addition to what was said, you could add choices that wouldn’t change much besides adding a few lines of flavor text. However, do use this sparingly since too many impactless choices might make readers feel as if their decisions don’t matter in the storygame. One way to work around this would be to change minor parts of some scenes or the ending based on these choices (for instance, the main ending could have a sentence where, depending on who the protagonist chose to save in a battle, the name of their best friend is altered).
Another thing you could do would be to add links for extra information. Whether it’s a small foreshadowing detail to solidify a plot twist, a minor location you weren’t sure whether to add in an earlier draft, or a worldbuilding/ lore detail you want to flesh out, feel free to let the reader explore it before looping them back to the main path.
2. Death scenes
One ‘easy’ way of adding choices would be to add death scenes. If you don’t fancy writing many different deaths, just write one or two death scenes and link all the different deaths to these pages. As you go through the story, think of potential ways for the protagonist to either die or reach a ‘non-winning’ ending, then add links to premature endings there.
You mentioned that you have one main path, but three other endings in mind, and the branching occurs in the last section. However, you could set it up so that the ending is based on a combination of all the choices that the reader made throughout the story.
For example: the reader gets to choose a way to respond to the antagonist, but on the next page, it seems like the choice does not immediately matter because the antagonist ignores their remark and the story continues.
If the protagonist chooses to make an angry retort instead of a peaceful one, you could add 1 to the variable ‘anger’. When they reach the last section, if the reader made enough choices motivated by anger (determined by their score under the variable ‘anger’), then this means they reach the ending where the protagonist’s anger is unleashed upon the antagonist.
Best of luck with your storygame! Hope everything goes well :)
Well, I do have to warn everyone who wants to put 10.000 words on their first page: be prepared that no one is going to bother reading your story for at least a good while or forever. Perhaps you may have noticed, but in most of the popular/well-read stories on the site, their words/page ratio is about 500-1000, 1500 is really stretching it and 2000 is straight up a big turn off for most.
But, yeah, think of it a little, but with the site's absolute obscurity and the unwillingness of many site users to read, fame might not be something you can obtain here.
As for tips: lots of people have already said useful stuff. One thing I have to add is that it might be easier for you to visualize your outline now as a huge map rather than a short story. It makes keeping track of choices and other important stats a lot easier and can keep your focus on the big picture. Something like this would come in pretty handy, especially when you are afraid to do something a little more extravagant.
I quickly made a small example of an outline: drawing programs are not necessary, colored pens and a notepad will do. It doesn't have to look fancy or something, it is just a helpful tool for yourself to use at your discretion. This example of a choice tree will also illustrate what some peeps are telling you about.
Pink represents the gauntlet style of branching.
What the blue lines indicate is the bottleneck branching.
The red is about the "false choices" one can choose to include. The green is again to indicate stat changes or when a certain stat is required to choose a path. Through the inclusion that stat, what otherwise would be only two endings, can now have three or even four endings without changing much of the structure!
Mix and match these techniques a little and I think you can make any linear novel interactive fiction.
As for my suggestions:
Minimal pain and time for your side: gauntlet style and fake choices.
A little more pain and headaches: +stat usage and bottleneck branching just like the others have suggested.
Addendum: Well, this is just my opinion, but it is easier to craft a story with the interactive element in mind from the very beginning rather than trying to wack an already existing thing into submission. It lets you just take more advantage of the medium this way and let you be a little more creative with how you approach branching, stats etc.
Some people just do whatever it suits them and do just fine haha. From what I can read from the old forum interviews, Endmaster seems to just write out a story from beginning to end and every now and then inserts another branching story whenever he feels like it, just like what you have been doing I guess.
Edit: I'm really starting to feel that the article: "Choose-Your-Own-Stories, Paths, and Writing" needs another update to make it a little more detailed considering these questions lately. Perhaps pictures and the inclusions of these suggestions would be nice to have.
Boy I need to get my mind out of the gutter. This IS a writing site after all. Why would the post title mean anything else?
Yeah, Yummyfood! Seriously, what is wrong with some people? ^_^
I, sadly, have to admit that I too had my brain think of something else.