The concept is great, but having both harvesting and entering the submarine mapped in the same key made playing the game frustrating especially since you could only enter the submarine when you were near enough, which meant that it was also super easy to get stuck if you fell somewhere too far away from the submarine, for example the beginning area, after venturing further. This meant that

the submarine was likely to be too close when you were trying to harvest a plant and thus making you enter the submarine rather than get the plant like you inteded.

I like the audiovisual side of the game, but harvesting (or entering the submarine) certainly needs a key of its own. The pause manu could also use a "resume" button; I pressed the "return to the menu" at the beginning of the game multiple times since I just assumed that it would let me begin playing and didn't read what the button actually said - another button would've forced me to actually read the text instead of just assuming that the single button in the menu will just close the menu. In addition to that, I think the game shouldn't begin with the pause menu to begin with; if the player wants to turn the audio off, they can open the menu by themselves.

Overall, this has potential to be a fun game but the controls need some polishing.