Thank you! Indeed, there are two horror games, Lurking and Stifled, that use this effect. I think they come from the same developer actually. There is only one older platformer, where the effect is different but it's even more beautiful in my opinion, Devil's Tuning Fork.
For the 3rd puzzle, it might be on me because I'm expecting the player to figure this out on their own. The platforms themselves emit a low sound and soundwave when starting/stopping. That should be your point of reference along with a light near the stairs. After that try "looking" around more with echolocation.