This was a super charming little experience with cute art and fun characters. All the assets come together nicely to create a very playful and relaxed environment which ties in nicely with the gameplay.

First I want to talk about the art. While overall I think the sprites on the title screen are fine, I get the feeling that it was all a bit rushed. There's a big variety of pixel densities going on with a mix of pixel art coral, the sorta pixel art machine, and not pixel art UI. I've also made my fair share of rushed titles, but when you can spare some extra time to make something special it can really help make your game feel cleaner since it directly impacts the players first impression.

 Additionally it feels very static, especially since I know you animated the machine in game. Some easy changes I would suggest to really bring the title to life would be to use the animated machine, have the lights sway side to side, and maybe have the coral move just a bit.

Moving on, I really like the different designs for each of the sea critters. It seems like a lot of the focus was used here for the art and its well worth it since they are the stars of the game. Additionally the unique designs and color schemes they each have makes them easier to tell apart which helps during gameplay when I had to go back looking for somebody.

One small thing was that the player's feet would raise up during the idle, unlike with other characters who's feet stayed firmly on the ground. Most likely a quick fix by moving his art up a pixel or two in the sprite (unless this was intentional and I'm just interpreting it wrong). 

Also, the environment felt pretty basic but since the gameplay was all located in a pretty small space this doesn't feel like an issue. However when the tile pallet bends in certain places there are some hard lines that border the black void. This doesn't look great and probably could have been avoided with some additional tiles. I would also suggest looking into Unity "Rule Tile", which will automatically place the correct tiles for you once set up, so you don't have to do so much manual work when designing these kinds of.

And the little pickups all over the map look good, and there's a great variety. The bobbing effect also helps sell the kind of cartoony vibe of the game, although one minor suggestion I have is to desync the bobbing since it stands out when you have so many next to each other. This could be done with a script on start that run the following: 
myAnimator.Play("My Animation Name",  0, Random.Range(0f, 1f));

As for the audio, I really like the gameplay and victory music as it fits the cozy underwater environment that the game has. However I'm not as fond of the water sounds that were used on the title. I get that you wanted to show off the "Dark/Scary" machine, which the music does sorta help with, but its very jarring on startup and doesn't really fit the vibe of the rest of the game.

However I do like all the "watery" sound effects that were used throughout the game. They really bring it to life and add great player feedback. I wasn't quite as fond of the abstract "ding" sound effects, like when picking stuff up or talking to people, since they were less fitting/satisfying in my opinion, but they still get the job done. (Were those made with sfxr by chance?). On their own these generated sounds are usually ok, but in combination with more realistic sounds they can sometimes stand out.

Next I want to talk about the gameplay. The player movement was a bit stiff and he can get stuck on walls (This is caused by the many boxes a tilemap creates for the collider. Adding a composite collider will avoid this). Additionally he also moves quite a bit faster when moving diagonally. This can be avoided by taking your movement vector and normalizing it. Overall this is barely an issue since the gameplay is mostly unrelated to the movement.

As for the map design I think you did a good job of making something that feels natural while still including space for everything you need. Its easy to go way to big with these kinds of maps but I think you spaced everything out nicely. 

One complaint I do have is putting the "Strange Machine" behind the player on start. I (and possibly other players) walked directly right on spawn without paying any attention to what was behind me, and didn't realize that was the machine they were talking about until I walked back that way while exploring later.  I think it would have been better to have that first npc on my right when I wake up to explain what's going on, then have me see the machine as I walk to the main hub. That way I understand what I'm seeing and the player won't miss it.

And lastly for the writing, I think you did a great job of giving each character a unique and fun personality. I especially liked the quests that involved bringing characters together since it forced me to remember each of them. Additionally when they reference each other it adds some worldbuilding and makes it a more believable community, rather than one off joke characters.

However the ending did feel very sudden. It gets the job done, but maybe something like having the player walk back to the machine after collecting enough allies, and then giving a couple lines of dialog about how they would have had some better pacing.

Overall, this was a great entry with lots of personality. I apologize if this review was a bit much, but I'm doing this to all the games from this jam as I think critiques help us grow.