This title feel deeply personnal (the vocal version) so I feel like my opinion is pretty unsignificant, but since it's part of the JAM :
Loved it ! You managed to get an underwatery vibe without using the more obvious soundesign we usually find to inspire water. The track is incredibly well made and just a great music overall. If I had a complain to make, I'd say it may be a little too "standalone" for a game, but I feel like an assh*le making this comment on such a great piece of art.
You don't need to feel like that at all x3 You're entitled to your opinion and it's totally valid! I also don't think it would work in a vast majority of games, haha. That's why I view it as an ending theme rather than a BGM that would play during active gameplay.
If I had more time and had known about the jam sooner, I would definitely have tried to make a full OST instead, but since I was so short on time, I figured, if I'm only gonna make what is essentially 1 track, it needs to be either an opening or an ending theme, haha.
One of the things I like to do in my visual novel game projects is have an instrumental version of the main theme play on the title screen, and then once the game has been completed, switch to using the vocal version instead, so that's another way I would use it if I were putting into one of my own projects. Though, I still see it as more of an ending theme than a main theme!
Anyways, I'm just happy that you took the time to listen to it + thought it sounded decent :3 So please don't feel like an assh*le in the slightest cos it's all good! :D
