Beautiful game! Fantastic atmosphere all around with the graphics, characters, and music, and I like the climbing / platforming. I will definitely will get this when it's fully released! The demo is awesome and almost already feels like a full game, I've played through it a couple of times.
I'm sure the full game will have more rock/climbing types, but if you don't have these already, these might add some additional interesting interactions:
- A rock type- maybe slippery - that you can't grab mid-air (need to be touching a rock with at least one hand). You could create longer traversals requiring both hands with this, or make the player leap to a different rock before moving over to it.
- Using a rock material but inside of a crack, rather than protruding from the mountain face, to simulate crack climbing and adding some visual variety.
- A rock type that you can only grab from above, or from below. If you maneuver too far in a certain direction you'll fall
I don't know if it's feasible for the scope of your game, but a custom mountain / level editor of some type in the final game would add a ton re-playability and community interaction.