When I realized how it works, the game was actually quite fun! It's a nice twist on a physics game concept that could easily be turned into a mobile game or something.
I think the reason it was confusing at first was because it's not immediately clear that touching literally any obstacle causes the climbers to fall through the map. The rocks don't look like hazards, they look like something you should stop at or bounce off of. To a player who doesn't understand the mechanics, it seems like you're falling off the wall at random times.
Something as simple as a particle effect appearing on the spot where you touched an obstacle, and perhaps an accompanying sound effect, might have been enough to make people less confused about why they fell.
Due to deadline we couldn't finish anything like "Tutorial", because we wanted to finish level design and test exports for bugs.
But you are right. It is confusing for most players in the beginning, about controls and rules of the game. There must be more indications (There is only one when you are low on stamina).
Thanks for your feedback, and I am really glad, that you liked it.