According to the comments, we did a hard game. It has been designed to be quite unforgiving (only one life), but still doable. And it seems that we achieved our goal here.
Later on, we added several difficulty levels. Instead of just altering some variables, we wanted to have a different experience for each difficulty level. That's why, on easy mode you have some additional visual elements which helps you to find your way out of the puzzle, whereas on hard and extreme mode, you get far more easily lost. I think that hard and extreme mode make you really feel what we wanted to share in this game.