Starting tomorrow night, I am giving up computer games for Lent. Withdrawal is going to be very hard. See you again after Easter!
iron sudoku is not a game. It's serious business. :) :)
One does not simply walk away from Iron Sudoku
Our perception of difficulty level doesn't come from the average time it takes to fill a cell but by the time it takes to fill the most difficult cells.
DING. I got hung up for a while on a really simple missed crosshatch. That skews my perception of difficulty. Other than that, I'll give it a 16.
UTH: So you don't think the total time to finish a puzzle has any influence on the perception of its difficulty? I'm just reformulating the average time assertion. What I'm suggesting is that perhaps you have noticed that the really difficult puzzle only differ from easy ones because of a few sticking points. Not many puzzle fight you at every step.