I was playing Pearl and tried to challenge myself to having to draw the whole solution it one go. Unfortunately it seems that once you draw a cycle, even one that wins the game, the whole partial stroke vanishes. Normally cycles are useless, but they're useful in this modification of the game. They're also useful for correcting small mistakes: when you draw
123_
__4_
when you meant
1234
__65
you can fix that by drawing a small cycle (34563 in the second diagram) instead of 36 + 3456.
Drew Morgan writes: