It's kind of weird how many games this applies to. They just get the character cliches ('bitchy younger sister', 'horny MILF' ) and throw together some plot and scenes with zero consideration, just making shit up as they go, then some character gets unexpectedly popular so they pivot to be more about that character (or at least squeeze in more scenes) and by a couple chapters it's a complete aimless mess which the author has no idea how to resolve (or even progress) in a coherent way because there was never any plan.
So, to actually be helpful instead of just whine, it's not that hard (I've done this a few times):
- Come up with your ending and what kind of plot you want to tell. Then come up with your beginning.
- There can actually be some minor stuff (epilogue) after the 'ending', technically what I'm calling the 'ending' here is the 'climax', where it all comes together. But 'climax' is too hur hur for a porn game.
- Figure out your core characters, in depth.
- Figure out the plot points (checkpoints) along the way you need to get from your beginning to your ending - these become your episodes / chapters. It often helps to work backwards from the ending.
- This does not have to be brilliant genre-defining (or -busting) stuff, generic popular plots are popular for a reason. Feel free to rip off any movies, series, or games you like, just change the chars.
- It will help if you can then work in one twist to make it memorable, but again not required.
- You don't need to write any dialogue yet or figure out any supporting chars. In fact, do not!
All this needs to be done before you even start! Now you're ready to start doing stuff:
- Figure out your supporting chars, maybe your MC needs a bitchy younger sister. Maybe you need an evil cop for this one plot point. You can be a lot looser with the supporting chars, just make their personalities consistent.
- Now you can start writing.
- Make sure your core characters stay consistent!
- You can actually be kind of loose between checkpoints as long as you get there, so sure, squeeze in an extra scene or two with popular character. Just make sure you're always working towards the ending and the checkpoints.
- You can even change things, maybe significantly, along the way. Hell, it's almost guaranteed! Just make sure it's still consistent with your ending (or change the ending) and consistent with what you've done so far, and make sure you modify your checkpoints as needed and they're all still consistent with getting from start to end. You can even add or remove a couple checkpoints as needed, just avoid Game of Thrones / Wheel of Time Syndrome. There is rarely an excuse for one checkpoint to turn into ten.
And that's it. Sure, you can say 'hell this is just a porn game who cares?' but if you have significant amounts of dialogue and it's not just a stupid Miel wankfest then obviously you care and some of your readers get invested and care, and they're disappointed when it all just turns to shit at the end and they will remember it. Doing the above will make the difference between a good porn game and a great porn game - or at least between trash and 'well, okay.'
And as an added bonus, if you do need to cut the game short, then you can just rush through all the remaining checkpoints and still arrive at your ending in a single chapter/ep. Everyone will be able to tell it was a rush job, but at least the ending is satisfying and consistent. And all this goodwill will help you with your next game.