You said on the page that you're a beginner and asked for feedback, so here's an honest one.
The title screen tells you the controls ("USE W/S TO CONTROL THE NET") before the Play button. That's more than half the entries in this jam managed, and it's a genuinely good instinct. The theme is likeable and carries a small environmental message without being preachy. The blue pixel art water with the lighter ripples and the sand strip at the bottom is clean and pleasant, and for a first project the palette is well chosen. The scope is also tight and realistic for a jam, which is the right call. A simple game that works beats an ambitious broken one every time.
The problem: I couldn't start. The PLAY button didn't respond to a single or double click, and W, S, Space and Enter did nothing either. I was stuck on the title screen.
Almost certainly this is the cause: the game window is wider than the browser view (there's a horizontal scrollbar at the bottom), so the button's clickable area ends up somewhere other than where it's drawn.
The practical fix, since you asked: in Unity's Player Settings, tick the resizable canvas option and test in a small window. That single change would open your game up to everyone. The rest of what you did is on the right track, so it's worth doing.