Comment by JJCUBER

Increasing the difficulty over time sounds fun! As an idea, there could also be multiple endless modes which either have faster/slower ramp-ups, start "further into" the difficulty, or just have fixed "easy," "medium," "hard," and "ramp-up" (curve).

To be honest, at first, it was less of an urge to get "one more turn" in and more of an urge to make sure I had beat my original high score. Once I surpassed it, I was trying to see how long I could survive without running out of time. It was at that point where I realized I could keep going forever without running out of time (I could recoup more time than I spent, and I would regularly hit 99 capped time). After this revelation, I set a goal of going until my hands got tired. Once my hands got tired, I almost succumbed to the "one more turn syndrome," but after moving (I believe) one piece, my score had a nice 3-digit repeating pattern and was a round number, so I called it quits.

Luckily(?), my hands have made it through games that are far more torturous on the fingers (though it has been a while).