Really cool concept and it's definitely brought to life by all the 3D models! The fish, the sub, the chests and all the other scenery pieces were really brilliant, so simple and so well done! The look of this game is what makes it stand out from the rest! The sound design also really added something special to the experience.
The shooting mechanics were really smart and I liked how their direction was controlled by the mouse position. The barrel roll was pretty comical as a reference to the iconic line in Starfox "do a barrel roll", it's just unfortunate that there was no sideways movement for the sub.
The ending was a bit unexpected and it felt somewhat premature.
Overall though it's a really nice game.