Cool style, good shell mechanic.
Controls could use some work, and I took off the shell in mid-air and it didn't fall to the ground. I tried to booty-scoot into it mid-air but that's harder than it sounds. Maybe fix this (sea) bug ;) Could also use some light, tropical music.
Good first puzzle as well. Teaches you how to go without shell and to return another way to retrieve it to move forward! Good marks!