Alright!!
Really amazing platformer with GREAT way for adding the challenges. Specially the 'You are the Enemy' challenge that you wanted to do with the lore. I was also planning on implementing that challenge with the lore but like you, wasn't able to do it. However, I do think you shouldn't have revealed it as you are going to update the game after the JAM.
Now as for the Audio aspect, really good crisp audio. There are a few things that are already mentioned by others down that you should take into account while updating the game later:
- Lighting of the game. It does get really dark. But if you wanna keep that dark theme, maybe you can find a way to light up the platform, using some white lightings or something else
- The text should get more clear as you don't people to be stuck reading the text in the level while they are being chased by the mist.
- Player movement - I think you have implemented it in a way where player moves forward a bit even when he stops moving cause of inertia. Its good but messes up the flow when you are short on time and you fall off the platform by a split second. Yes it accounts for an added difficulty so maybe you can touch up a bit more on it.
Overall really good game. And can't wait to play it once you have updated the game again after the JAM.