I'm currently working on a new version to fix bugs, clean up some graphical issues, etc. I may release a new demo that only includes half the game instead of 75%. But to be honest, I'm less concerned about money than that people enjoy playing it.
A bit late to the party - if the demo passwords work in the full version, I don't see a problem with it. I would agree that the demo was too long if I beat 75% of the game, then had to beat that same 75% to get access to the last bit lol
The same passwords should work in both the demo and the full version. I wanted to make sure people wouldn't lose their progress in that exact scenario.