Yeah the screen shake is really too much... Originally the curse was going to intensify gradually over time and when you make a wrong decision. But I ran out of time and was unable to implement the rest of the puzzles.
You are correct that it is linear. That's a really good idea for an exponential increase!
I also didn't think about it making people sick... I plan to add an option to disable the shake completely (adding a curse meter to the screen) when I implement the rest of the puzzles.
You'll have to check it out again!