@arend-hintze I tried running it in Processing 3.5.4 and it didn't run but it gave me a more meaningful error. At first it required the directory to be named the same as the sketch. It then ran the start screen with music. The mute toggle worked but when pressing any key to start it crashed with: textMode(3) is not supported by this renderer. Processing 4 still does nothing.
Update: by commenting out the 2 uses of textMode(CENTER) in Scene, I got it to work in 3.5.4. A truly baffling bug.
It's an interesting game and definitely on theme. The rising water is definitely an unstoppable force. I did feel that the character was quite small and the movement could be a bit awkward at times. Also, I felt that seemed to be a fair amount of unused screen space, but that might have been that I didn't live long enough to make use of it.
Other than that, a solid effort. Well done!