I thought this was a pretty fun diving game.  I liked that there were different Islands that needed different items that I was diving for.  Once I realized I could go to different locations from the main Island I started having a ton of fun.  There were a couple of things that I think could make it a little easier to play like explaining how to use the stores and how to travel around.  The keys were a little far apart too, it just took me a minute to get used to how the buttons were set up, I think if all the keys I was using were next to each other so I didn't have to move my hand so much it would make it more intuitive.  The HUD was a little to big I think for diving as well.  It was hard to see what was on the bottom of the screen because the UI was blocking it.   The last thing I think could help is adjusting the colliders sizes, I was hit by a shark a couple of times even when I was a pretty good distance away from it.  Fun game though, You did a great job with the art style and environment.