I tried your game. Gotta say the music was very atmospheric and very fitting to the game. It left me both stressed and relaxed at the same time, which I thought was impossible. Apart from the fact that I punched a hole to my monitor and my keyboard looks like burnt minced beef, I really like the smooth motion, the water, and coupled with the music, your was very relaxing. Also your attention to detail was very good(as time runs out, your character's fade lessens is pretty cool).
I would suggest to add the gems in the tutorial section to let the player's know what they look like, cause the first gem I found was the yellow one and I was confused for a second why the starfish looks like an octagon.
Overall, I think it was cool game.