I like the logo a lot! The art is nice and clear, and the music absolutely rocks! The controls are tight, and I like the concept a lot! In particular, I like the concept of changing into different elements to get past specific obstacles.
About the element changing, I think being able to change it using the mouse wheel would've been interesting too, considering that you can attack using LMB.
I did notice that the Fire wall in the 2nd stage can be passed through with either the Fire or Water elements. Since I'm not sure if it's intentional, I'm pointing it out here just in case.
Enemies being able to damage eachother as well as dying from falling in the abyss were very good touches, and I also like the parallax effect a lot. Would've been interesting to see what you would've come up with if you'd gotten a bit more time to explore the gameplay concepts. This was a very enjoyable experience with awesome music!