Very sweet album.
First track Overworld theme: Good composition and render of emotions. Small thing I would look for at 0:56 when you want to do the rallentendo, its a great idea but you rushed it to go back into the loop straight away, let the music breath for a moment with a little pause then continue I think it would embelish even more your composition.
In and Out of Water : You get the general idea of putting low pass filter but I think you can probably add something to make this very different from when you are in and out of water like an instrument or musical element that will truly indicate the difference on top of the low pass that is not water sound design. Btw the sound design was a nice touch too.
Adversity I think everyone talked about it and you already know what to do.
Good job !