Just a suggestion: instead of forcing the players to stay and solve the puzzle, allow them to leave, but every time they sleep , they dream that they are back at the tower and are unable to dream of anything else until the curse is lifted. That keeps player agency while fitting with the dream/sleep theme. Otherwise I like the theme and feel.
Viewing post in Zerzura's Zenith jam comments
Thanks for the feedback! With your suggestion in mind, would you recommend dropping the possibility that the PCs might turn to stone as well? I was trying to instill some urgency in resolving the situation, but I'm cognizant of the dangers in trying to force a party to stay put. (In my experience, parties prefer to do the opposite of whatever a GM thinks they're going to do...)
If I was running this for my group, I would turn that 1 in 6 chance of complete stone to just 1 hand or foot turns to stone: A stone hand is a penalty in combat and makes two-handed manipulations impossible. A stone leg makes movement and dex checks/saves difficult.
Future 1-in-6 failures would spread from the foot/hand up into the arm/leg and incur a greater penalty. That way the character can continue playing with the sense of urgency you are trying to cultivate. But maybe I'm just too soft-hearted, lol.