Nice! Well it's very hard, even if you know the controls after 200 deaths and sometimes, when you are on a wall, the jump height isn't really always how it should be. For example if I hold long the character sometimes jumps the actual height he should jump but sometimes a really short height (even short than if you tap spacebar)...
The game has a nice diversity, I didn't get far but already after the first narrow section a new mechanic is introduced (the platforms that switch when you jump)... maybe a bit early but thats ok i think.