It's hard to define on the jank--I think it was mostly that I tried climbing the right first which might have been an inadvertent Getting Over It with Bennett Foddy type of experience, and it seemed like if you got into the 1x1 notches between 'jumps' it was not very easy to jump out again.
The only other nitpick here is that I don't think I had a health bar/indicator.
For the record the note about boss health is only for boss 1. The main one actually felt about right.