Cute little game! Liked the cutscene at the start, and the simple but fun gameplay! Music was also great. Atmosphere was nice but I think that it could use some more background elements, such as other sea animals, plants... Just something that adds life and depth to it. Also, maybe it would be interesting to have something to collect while playing, it could be great to guide the player a bit and also make the gameplay more dynamic.
Great game! Keep it up! ;)