Hello! Thank you for checking our game ^^
The water was made using this shader https://godotshaders.com/shader/another-water-shader/ - but edited to remove foam, and depth effects which are not supported on the web because of lack of depth texture. For the color and normal map it's using a seamless FastNoiseLite texture with color ramp clamping the top and bottom values.
https://godotshaders.com/shader/simple-sobel-filter/ is a screenspace effect used for the outlines (very subtle because it darkens the game considerably), just with `color + sobel edge detection` line uncommented and 'g' value plugged to alpha.
Did the sounds not play for you?
Let me know if you need more details :)