I found a soft-lock:
The first time you practice the vanish skill you can be captured by the guard and reach the goal, at the same time. You can do this by, while the time runs out, moving from a 'seen-space' to the 'goal-space(line of spaces)' the guard will capture you and kick you out, but before that the ninja congratulates you. After re-entering and right before moving to a 'goal-space' the line of dialogue from the ninja telling you to turn back, since dialogue cancels your vanish, the guard throws you out again.