Thanks for the feedback. If I had time to implement any enemies, I would certainly try to find a way to incorporate the climbing mechanic into combat.
The places where you can't climb because of a block above your head were meant to be overcome with the boots upgrade, but it ended up not working quite as intended, so due to time constraints I decided to leave it as it is. It's still possible to get past obstacles with it, but much more difficult than I wanted it to be.