Thanks for playing, and the feedback!
I put a lot of my effort into the atmosphere of the game so I'm glad you liked it!
Yeah the combat doesn't have nearly enough feedback. I basically had a choice later in the jam of improving the combat or improving the rest of the game and I chose the latter. I definitely plan to update that post-jam. The rifle does do damage, but the blood puff that spawns when you hit an enemy flows out from the enemy model, and since the shark moves so fast it effectively obscures the particle effect.