When I heard "platformer with hard controls" I instantly though "Oh no, not again". However when I played it, I was pleasantly surprised. The control method is actually quite clever, and I can't remember playing anything similar in recent memory.
With that said, I feel like this game would suit starting with a more conventional traverse, rather than instantly going into a climb. The main issue is that jumping with these controls is very hard when you first start, so easing the player in might help at first.
With that said, this is a very interesting game. Well done!