The game is quite good for a first project, simple and “complete”.

Few suggestions:

• Add progress bar to loading screen
• Animation does not show final frame(s) when hitting an obstacle. This creates sense of “unfairness”, as the game displays your fish far away from the obstacle yet you lose.
• Maybe add concept of “lifes” to make more room for gradual difficulty increase
• Game spams console with errors: “RenderPass: Missing resolve surface for attachment 0. Are you tring to resolve a bindMS rendertarget?” (I play on Firefox / Windows)

The menu music is great, and the overall art is also very fine. Game concept is easy to learn, hard to master. Good start.
What you are missing is the feedback.
The player needs a satisfying feedback, when smashes the fish to the ground. For eg an animation with splash when it touches the ground. (If it's random at every time -> the better) And also a popping sound when it happens. You know, I have to WANT to do that smash again. And again. And again. It must be like those bubble wrap foils 😉 You can't stop popping them 😄
Maybe if the fish will rotate somehow when you press the button... Now it remains always 100% horizontal and it feels so mechanical. 
You do all game mechanic well, but at the end only one thing that matters: how the player will feel it. 
Think about Super Mario. Without the jingling sound of the coins at pickup it will be a mediocre experience to collect them. It's a tiny thing, but gives a huge feeling to it.
To fine tune this, you need a lot of experimentation.
For example you should have a fading +1 popup above the fish when it pops to the ground to indicate the gaining of score.
Or you could try to move the fish above or below randomly to the starting height after a pop instead of resetting to the fixed height.
Try out new things (lots of them), and some will just "click in" the game 😉