Thank you for enjoying my game!
I did spend a good chunk of development time into tweaking the movement speed and stamina duration to try and make it feel right, to limit the time spent climbing but allow for decent lenghts of climbing sections with possible dangers.
I was trying to think of a sound effect for climbing, but I couldn't find a good fit for it and so I just decided to go with the music...
As for GIMP, it's not working so bad for me! I'll plan on maybe getting Aseprite in the future, as I've heard good comments about it, but for now I'm used to GIMP.
Thanks again :)