I did play timed mode, are there any other differences than the timer?
Maybe obstacles in the water could add some more, but overall i think the concept is really great!
Obviously still there isn't a lot of gameplay there, I like the concept tho!
If you are planning on working on the game some more, I would maybe try to make the controls a bit faster, right now they feel a bit floaty(also while not floating).
I think the glide mechanic has a lot of potential for really interesting powerups!