Amazing how it goes from one of the most relaxing games of all, to the opposite end of the spectrum. The sound effects in particular are very soothing, but the further you get on, the more you encounter a feeling of dread as seemingly unsolvable situations are involved, with more intersections of colours, and more to lose when you accidentally click on the wrong side of the chain...... basically, it's best towards the start when it's nice and relaxing.
The rise in difficulty isn't particularly fun in my opinion, though people with different taste might find otherwise? So long as you don't attempt to ever use trial and error.