Let’s look at my current WIP. It looks like I started notes in January 2024, with the idea bubbling around for months before that. In April this year I had a chapter mostly done (out of 10), some tech prototyped in the previous year and had got my accountability buddy on board. We had suggested a week per chapter, plus some tech time, plus some design time, plus some slack time, to take us up to an August deadline.
This was… optimistic. Life is cray. Writing is hard.
I’m currently at 20% written with a current sprint underway (doing about 5% a day). It’s maybe achievable.
My previous project, Hand Me Down (post-mortem here), took about a year of regular work, with a week-long and month (?) long sprint in the final 6 months. That required a lot more coding as it contained a TADS 3 game, a straightforward Twine game, and a storylet-based Twine game. I wrote the straightforward bit in a week, then rewrote it in a week. The storylet structure took a few weeks, but was tough, complicated writing.
Compare to One True Love, a game I wrote for SmoochieComp in about a week or so. That was just Twine with a storylet structure, but it was simpler.
There are a lot of variables in these numbers. Sometimes a game needs to simmer. Sometimes you can just bang it out. Sometimes the gameplay is a lot more complex than you expected. Sometimes you rewrite something multiple times.