Nice job! The level/game design here is creative and works great -- having so many different characters occupying the space, designing their interdependence, controlling the options available for character-switching, etc., all while ensuring that it functions in whatever way players might go about the tasks -- that seems challenging, but I played through to the end and it worked smoothly. Nice! I liked how you can sometimes see characters behind grates, too. The spider enemies were also great, I like the animations.
The moving platforms did their job, though I noticed that when I landed on them (after their motion was turned on), I was stuck in the falling animation and couldn't move laterally. When I've encountered this kind of thing in development, it has usually been because the player isn't detecting a "Ground" layer/tag; perhaps it's something like that?
I also encountered the scratch/static noise at the end of the Hymn sound effect that another player mentioned. I think I've had that issue on sound effects when using .PlayOneShot(), if the loop box on the sound hasn't been unchecked. Not sure if that's helpful feedback, but I thought I'd mention it in case it is.
Nice work!