Your composition is immaculate, as always. This is a very inspired soundtrack overall, the story setting and music tie together perfectly, beautifully highlighted the world that you've created. Very impressive stuff, exploring traditional regional instruments and styles and incorporating them so seamlessly into your music. It's a lovely soundtrack altogether, composition wise there's very little critique that could possibly be offered. "Ascending Starlight Buff" was my favorite, the high energy and time signature work really well and it's just a fun track all around (and thanks for teaching me what a jig is!)
Production wise, there is a minor issue with some crackling/popping on a few of the instruments you used. Could probably be fixed with some overall volume control or EQ, but it's relatively minor and doesn't really detract from the experience.
Storytelling wise - I know this is a music jam, but you clearly spent a lot of effort on it so I'll throw in my two cents here. Firstly - and this one is also pretty minor, probably unnoticed by most or explained away easily by suspension of disbelief/"it's a world with magic and selkies and spirit creatures, does it really matter?"/etc kind of thing - if the main character's father died in the middle of the ocean, how does he have a grave so far in land, and in a place of significance that only he knows? There's no presumably no family left to bury them, unless we are assuming that the mother did it; which could be possibly highlighted and developed with subtle hints or clues along the way/afterwards. That kind of detail is probably outside the scope of this jam, but I thought it was worth at least mentioning.
My bigger concern, though, is that I'm not remotely sold on the idea of the main character having any reason to return to land at the end of the game. Yes, the motivation mechanic has dissipated to represent the resolution of inner tormoil, but the character now has no connections to the land other than a gravestone that might be a sentimental place to visit once in a blue moon. It's a nice idea to leave the player to interpret the main character's choice, but in this case I feel it's not truly necessary. The selkie's conflict has been resolved, she can now return to the ocean to live free and potentially be with her mother. Alternatively, the ending could show the selkie returning from the sea to interact with a human of the same age, showing her love for the land and the continuation of the cycle.
Regardless, stellar submission overall! Your last year's submission was high quality, but didn't resonate with me personally nearly as much as this one did. You really nailed it here, great job!