I think the main issue was dramatically underestimating the amount of time it takes to make even a short RPG in 3D by myself. This seems to be a common issue among indie devs; human minds seem to be especially poor at predicting how long things will take, especially if they haven't done them before. It's still a short prequel, but even making one of those takes years.

I played that game OMNO recently, which had about six hours of gameplay. And the solo dev (who didn't even do the music) spent like five years on that!

I definitely don't intend to spend 5 years on this though.