Hello, and thanks you for playing our game !
For rewinding in the last level (the Land), in the lore of the game, the TV narrator (Rowdy) have tweaked the rewinding process here to just make the terrain disappear (he have full control of everything in the game). So, in this zone, rewinding is just affecting the terrain below the player.
For the audio level of Rowdy (the TV), it is low because we have not correctly setup Audio Sources, so you'll need to be very near of he to be able to hear it correctly. I will probably fix it after the game jam.
Anyway, thanks for your opinion !