A tough but fun game! Pretty much the same as other comments, although I would add I think it'd be great to have something that makes it a bit more obvious that you are currently climbing (rather than just noticing you're not falling).
I implemented some animations and sound ex to show that you are currently climbing, but maybe that wasn't clear enough and I should have an icon or maybe the character show in some way that you are climbing... Definitely something to think about :)
