Ha. If you find out without help, you'll be a god.
I found it without help. Tremble before my powers!
The game actually gives you more than enough hints to find that room without help:
First off, when you first reach the room in the lower west portion of the map you might notice the chicken-size tunnel in the ceiling (which also shows up on the map). This is a hint that there's a room above that.
The second hint would arrive either by accident or when you're scouring for chests. As part of the process of filling in the map while treasure hunting I was flying through that area by doing the Superman move from high points when I hit the floating block right above that room. Now, well-designed pathfinding/Metroidvania games don't waste space, so the fact that there was a block right in mid-air suggested that it was there specifically to halt your flight.
The next question would then be, is the block there to stop my flight so I can reach something below in time after hitting the switch?
One attempt to do that later and voila! Fifth mask piece get!
First off, when you first reach the room in the lower west portion of the map you might notice the chicken-size tunnel in the ceiling (which also shows up on the map). This is a hint that there's a room above that.
The second hint would arrive either by accident or when you're scouring for chests. As part of the process of filling in the map while treasure hunting I was flying through that area by doing the Superman move from high points when I hit the floating block right above that room. Now, well-designed pathfinding/Metroidvania games don't waste space, so the fact that there was a block right in mid-air suggested that it was there specifically to halt your flight.
The next question would then be, is the block there to stop my flight so I can reach something below in time after hitting the switch?
One attempt to do that later and voila! Fifth mask piece get!
That deductive process is what I love most about this genre, and I'm happy to say Drinkbox really understood how important figuring those things out was, at least for the secrets. It was still there for the main game, but far simpler. Maybe a little too simple, really.