The YouTube algorithm showed me your video a few days ago, and now I am here.
I 100% understand that you are in the early stages of this project; I have my own project that is baking. So I say all this in good faith:
To start, I can see the beauty in what you are making. I liked watching a school move together towards the food source.
This is how I approached playing your demo:
I wanted to see what you had to offer, look at what you might be either trying to do or looking to do in the future, and I wanted to try and break everything.
In the early stages of the level, I would just instantiate a ton of food for the one little guy. Shortly after the second guy came in, the first fish "died." I am not sure if that is accurate to say. His face was slightly in the floor and he wasn't responding to anything. His hunger was also 0.
After being able to spawn minnows freely, my "dead" fish sprang back to life. Note that I spawned a large amount of fish to see if I would crash. Nope, no crash! But many of the fish seemed to run away. Funny thing, after the group started evolving, one of them went out of control and turned into a giant goldfish way bigger than the level itself. It was hilarious. What was even more interesting is that once the level was inside the giant goldfish, the missing minnows came back. At this point I stopped playing by force closing the game.
I am sure you are aware of all the bugs I encountered, and that you have a vision for what you will be implementing, but I thought I would mention things that I would not expect to see as a player just in case:
1. giant goldfish. - this was hilarious, but clearly not what was intended.
2. unlimited spawns for both food and fish - I have no doubt you will limit this in the future as there are clear problems with giving players that level of freedom.
3. spawn placement - new food can be reliably instantiated when your mouse is outside of a certain radius. When it is inside the radius, you can only spawn in certain areas. As far as I can tell, it might be due to some of the lilipad stems being on the same plane as where instantiation is expected to occur and thus stealing focus from the player and disallowing spawns. idk though. just a guess. Also, the spawns are always a calculated distance from the mouse but always on the closer side to the center point of the aforementioned circle. it seemed a bit odd and felt imprecise as a player. My guess is that it is just a quick fix for something. if it is intentional, maybe a custom mouse pointer that indicates where both the pointer is and where the spawn will take place?
4. camera - I like the "fish tank" execution, where you are basically on the outside and can only act in a 2d plane. being able to move your camera around in 3d could be nice, but probably not necessary for your target audience. Clearly, the zoom in/out will be limited, and I am guessing you will put in some sort of panning movement. I also noticed that the first button that I pushed to get out of the "focus on fish" cam was Right Mouse Button. But that did nothing so I tried the clicking out of the fish, near the right side of the screen but that did nothing. Unless I am mistaken, clicking near the bottom of the screen is what gets you out of that cam/angle.
5. feedback - obviously, because it is so early in dev, there isn't a ton of feedback given to the player for actions they make or that the fish make. Meaning, when the fish eats food, you would really only notice when it is done if it changes size/color.
All and all, I like what this can become. I can see me putting it on for my younger kids to play. Anyway, this was maybe more than you needed. But I hope it was helpful in some way. Keep up the great work!