I've just tried your game. After a first false start which crashed the Windows audio engine (forcing the PC to restart), everything went without a hitch. Unfortunately, I did not understand how to continue beyond the mushrooms (I tasted all of them, hoping to reach a size that could allow me to climb on one of them and reach the heights, in vain).
Despite this, I enjoyed the trip, very strange but pleasant, where the sounds depend on the elements around the player. The background "music" is unfortunately not very musical, without harmony or melody, which makes it fairly neutral, despite the change in timbre and tempo: this is often the case with adaptive sound backgrounds designed from disparate elements, played/orchestrated by standard adaptive music tools. But in such a quirky and conceptual world, it works quite well (orchestral music probably wouldn't have echoed the graphic elements the same).
I dare not imagine what I missed by giving up the game too early, because I feel that the developer has imagination to spare. A good job of creating a sound environment, which is the main goal of this jam.
Viewing post in Fallen Down the Edge jam comments
I definitely went with a more generative ambient musical style as opposed to something with strong harmonic progression. One thing is I didn't totally exploit my custom adaptive system, one of the things I didn't have time to do was create more than one set of pitch and rhythm patterns for each of the musical entities in the scene, so as you observed, the music in each area is pretty static despite the tempo and scale changes.
As for what you missed, it's a little obtuse, but there is an ending sequence if you jump off the edge into the chasm.
Thanks for the feedback!