This is so sweet! The music choice and the little bubbling sound effects make this just a wonderfully chill and touching little experience. The tank is really lovingly detailed, and being able to turn the lamp is a very nice touch.
I do wish their was a little more interaction, even just by having the lamp affect the lighting on the turtle, or if it could go behind the castle or seaweed. I also managed to get the turtle stuck off screen accidentally by spawning some food at the bottom of the screen, leading to it to swim presumably forever to try and catch it.
This is again really wonderful, and has been wonderful to keep poking at even as I write this. Great job!