Interesting concept.
Could do with a bit of instructions. I thought I soft-locked myself right in the beginning, when I held space for a while, ran out of "stamina" and fell to the ground, unable to recover, until I realised I need to climb up the nearby boulder. Then I got stuck again later when I was hanging from a boulder and tried to climb up the side wall, but couldn't recover stamina, not realising that you can't grow on the side wall (that looks fairly similar to boulders that you can grow on).
It's a bit too easy to move alongside a boulder without being attached to it, so you just randomly start losing stamina. And the camera could be sped up a lot (then again, I'm always turning up mouse sensitivity in games).
An option to mute the music is also always appreciated.