I thought it was kind of fun, a bit challenging at times. I do have a few suggestions though:
1) The music. I have to be honest with you, I didn't particularly care for it. Beyond that I didn't care for it there are times when it is preferable to have a mute in a flash game without muting your computer. Though I do understand that you are obviously fond of the music I would suggest adding a mute button.
2) I didn't particularly find the hints helpful. Though I do understand that you don't want the hints to be dead giveaways, it would be nice if they were more than just vague hints (or seemingly not applicable). Looking at the walkthrough given by Alexalmo, I am not certain if I finished the game by chance or actually found the proper differences. For example in level 8 I thought i was clicking on one with 5 lobed 'flowers' on it's head, and in level 9 I clicked the one that didn't get lit up.
I don't feel as though it needs a high score table or achievements, but it somehow felt like I was working towards noting come the end of the game. Also I didn't see the point in sending you back a level for clicking the wrong one. This would have sucked had it happened on a level I just kind of guessed on.
Ultimately it was funish, but rather on the short side and not anything I feel has any replay value. It doesn't seem to have any technical errors but it does have some minor annoyances. 3/5 7/10 and I think that is on the generous side of fair. Keep up the good work, and remember a mute button is never a bad thing unless it doesn't work.