There are a couple of suggestions I have for this game. I'll talk about some bugs first.
If you shoot at soon as you spawn, you will die immediately which is kind of funny. I suspect that this happens because when you shoot, you plant a bullet where you are and then get sent one tile back, but since you haven't moved anywhere, then the game doesn't know where "one tile back" is and just leaves you on top of your freshly spawned bullet, killing you.
Suggestion: On spawn, set the player to be facing one of 4 cardinal directions and either add a directional sprite or an arrow telling the player where their boat is facing.
Sometimes, (not sure if this is intentional) I'm just unable to fish on tilted tiles. Whether pressing shift or enter, nothing happens. I'm not sure why this would be and so I have no suggestions for this :/
Overall, I think it's a fun concept with some potential to be a fun arcade game!