Whoa, this is a piece of art! The slow dialogue at the beginning helps increase the tension.
Unfortunately, at some point I got stuck in a respawning loop and couldn't finish the game.
If I had one suggestion, it would be to make it clearer what we are supposed to do when diving. I suppose the game has an end, but I couldn't finish it because of the loop (bug?).
I like the twist on theme #1, it is super original! I guess also Theme #2 is respected Yu is the buddy of Kou.
You feel some creativity and personality in the game, which makes it stand out especially in a vibe coding game jam.
The scope is well contained, which gives a feeling of completeness. Translations for a game jam are something we're not used to seeing in a traditional game jam: it's a nice touch :))