Hey @Gower, I think about these same sorts of “writer economics” questions too! And I’ve bought your gamebook and hope to get some time over vacation to dive into it. It seems like my cup of tea.
To me, the answer is: yes, absolutely write two 150k word games, IF you feel you can tell those stories within those word-lengths. I think it just comes down to where the story takes you and what you are trying to accomplish from the start. I don’t know that many of us think at the start, “I’m going to make this story 120k words no matter what.” That seems a bit…limiting.
So I guess it comes down to outlining, figuring out what choices and plot points are central, and then determining how large of a project will result.
When I first starting brainstorming Community College Hero, I knew there were way too many scenes to include in a single gamebook. I wanted to let the story breathe, and to include some lighter moments that are not really relevant to the central plot, but that are fun and allow for some social scenes and character development. To me it seems “fake” when every scene in a story is somehow woven into the main plot. But when writing a 150k book, the writer obviously has to keep things tighter and more focused.
So I solved the problem by planning a series. I figured that would pay much better overall (pretty obvious), and that it allows me to get feedback from readers and improve as a writer in each outing instead of cramming it all into one and not getting any feedback until I’ve published a massive 500k word behemoth.
And I guess your central question is really geared more towards official CoG games and the set payments that are offered to the writer, which aren’t really related to the word count. I would guess they want the writer to focus on telling the story that needs to be told (and offering the choices that need to be offered) as opposed to focusing on word count, which can be inflated by poor coding, lots of cutting and pasting, etc.
And for humble HG authors who only get paid by royalties, I think it’s perhaps even more important to focus on the economics, since 100% of payment depends on marketplace response. I am planning to make CCH a trilogy of 150k-200k word gamebooks, with the reader seeing about 30-40% of the words in each playthrough (which I think CoG views as the “sweet spot” between length and replayability).