I really like this game! The graphics look very good, and the music and sound design also fit really well. The controls are responsive, and I think that tying health and a light together is a really clever idea.
If you were to continue with this game, I'd put a way bigger focus on the light mechanic, as that definitely has the most potential, especially in a deep sea setting (perhaps you could incorporate anglerfish), and I'd drop the shooting. I don't think it really adds that much to the game