However really in the end it is about sales, and if they're bad then Nifflas has a problem.
Not necessarily. Everybody isn't in it for the money. Judging from how generous Nifflas was with the length of the demo, I'd say that an important objective of his with Saira was to gain recognition. But neither of us can speak for Nifflas.
This is true, and what many artists in multiple media formats seek. However it sounds like Nifflas has given even more of his time to Saira than his previous (and mostly free) games. There comes a point where you deserve/need money for your time whether or not that's your outright desire.
I don't really know that much about Nifflas so I'm just making assumptions.
Actually in response to the puzzles I had difficulty with, I didn't have much trouble after I found the Device Solver, I don't know if other people forget about it. Maybe it was just a me being forgetful.