Great take on the jam's topic!
I, unfortunately, encountered a similar bug as others where climbers with negative numbers first moved one stage down and then multiple stages up.
No worries, I still had fun playing the game and testing out the different cards. It felt very rewarding to play cards to push the climbers some times back when they were close to the summit.
I think showing the climbers stats when hovering them would have helped to keep track of their status.
Otherwise, again fun to play and great idea!