Great idea, it feels like I played the tutorial and then the game ended though. I don't think any of those were really puzzles.
Also, when I maximize my window, it shows some empty space in the corner, you can fix this by changing the stretch mode. Project Settings>Display>Window>Stretch>Mode.
Here's a document explaining what those settings do: https://docs.godotengine.org/en/stable/tutorials/viewports/multiple_resolutions....
In the html5 build, I cannot hear any sound, but I'm assuming thats just my browser/computer.
You are hiding the mouse, but I'm not sure why. You arent using the mouse for any gameplay, so it would be more convenient if you left it visible.
Really like the aesthetic. Super polished as well.