Wow! What a nice game.
The whole idea is very clever: combining the echolocation (and that shader...) with other perspectives (i.e.: Dimensions)... I really liked this game.
The only thing I would add (to make almost perfect) is two or more songs (of the same type of 'feeling' you are currenly using: calm + atmospheric), or a little longer song could do the trick too..., so when you are learning to play the game, so the music (which is very good) doesn't feel repetitive. (to be fair, it took me like 5 minutes to get the hang of it, by changing between Dimensions/Perspectives with "F", jumping across the platforms and everything... and so I listened to the song for a while later).
I also loved the shaders you used (Ripple + Outline together...), the effect is very interesting and supports all your game idea. I also agree that a V.R. version of this game would be awesome (providing you add a "vignette" effect to the sides, like they did in Resident Evil 4 VR, to help avoid "Motion Sickness" when you jump, run, etc).
Congratulations.