The big problem with rev 1.01 was that some of the levels were way too hard! But I think I found a good solution to this...

One of the important qualities of a good game is that everybody who plays it will eventually be able to complete the whole game, although some may finish quickly and others in a long time. Then, how do I set the completion time for each level so that everybody can finish it but expert players don't get bored? The solution I came up in rev 1.03 was to make the program automatically adjust the time limit based on the past performance of the player. To prevent the player from purposely playing slowly, I also pop up a dialog box that praises the player for completing a puzzle in half the time. This system works for me, and I personally find the level of difficulty always just right. Whether this works for other people, I only can wait for feedback.