I can honestly say this was one of the most entertaining games I've ever played. I loved the music (was looking for a link to it when I found you had been so kind as to add it already), especially the 'soft' track, it made the game a lot more enjoyable for me.
Beyond that, some were extremely easy, but the last one...wow, that one got me. I think it took me almost 30 minutes to figure it out and I liked that. Most games that claim to be difficult tend to be 'annoying' and stupid, this one was actually difficult without ever being annoying.
Great job and well done. I haven't checked yet, but if there isn't a sequel to this game I would appreciate it if you'd consider working on one, this was brilliant.
Thank you for hard work in making this.