The main issue with the first section of the Giant boss (so the climbing section until you hit his eye for the first time), is that you are only in "danger" when gripping on the vines. It seemed like the rest of the climb was as "safe" as a normal platforming section.
So maybe the Giant should move more to try to make you miss your jumps or something. At least something more than only waiting for you to hang on before trying to shake you off.
The rest of the boss was pretty cool though, with the rotating section when you are trying to save the golden knight, and with the falling debris as you are making your way to the catapult.
Have a great day :D