I am so glad you liked it, and that someone noticed how the stages line up !!
You are not alone about the start of the mountain climb, sadly most people I've watched play it get stuck there! We've edited it now to make it more clear, and made the NPC tell you helpful stuff about it.
The way is: hook on to the top yellow block, and then swing your body so you get close to the gray one while hooked to the yellow, and it will then turn yellow.