Theoretically, the concept of playing as a school of fish in which the amount of HP you have is directly proportional to the amount of fish you have is a fun concept, but sadly it doesn't apply here. You still die in one hit no matter how many fish you have because you only control the 'leader' of the school - and without proper highlighting, it's a nightmare to navigate the narrow trench filled with one-hit-death obstacles, especially when the rest of the school is blocking your view. This is why the second and fourth levels are the hardest because the amount of obstacles is too many while you can't even grasp the position of the 'leader' fish on the screen.
The game mechanic of having multiple kinds of fish with different powers is also a nice concept, but due to the level design and the amount of fish the game throw at you it's hardly matter to lose any fish due to leaving them behind when going through a narrow space, which makes the barracuda power essentially useless.
The hint texts are really fun, and I can definitely feel a personality behind it, like a proper guidance NPC instead of just some texts floating on a screen.
The graphics is nice, though there's nothing to write home about.
The music is chill and a great fit for the theme of the game.
Overall a 7.5/10, and I know this is basically an entry to a game jam but with more polish this could turn into something great. I can definitely see the work the team put in this, so keep going and never give up.