kalirion: (...) Since others are having a touch time finding it, I'll go ahead and say it's
Peak Condition, which google images found for me when I searched for <climbing game "acrophobia trigger">
Hello kalirion!
That is correct!
"Peak Condition" is a free climbing game with procedural generated 'blocky' mountains and a bleak atmosphere. Different than many other developers' attempts, you really have to plan and make your own route to the top of each mountain. Your two climbing axes are mapped to the left and right mouse buttons, and you need to keep your stamina for each one of them in mind while ascending to the mountain tops. (Short playing sessions are advised to not hurt your hands...) A tap on the space bar lets you jump up a ledge, usually at the cost of your remaining stamina(s).
Interestingly, a climbing session does not end when you reach a certain height for each peak, but you have to get down safely again, before it stores your score.
If someone wants to give it a try, here is its itch.io page:
Peak Condition Now, it's your turn (again), kalirion.
Kind regards,
foxgog
P.S.: (pictures) This expert level mountain with three peaks at 390, 410 and 437 meters I still did not managed to scale to the top. It can be really challenging finding and following a feasible route. This one also necessitates quite a lot of horizontal traversal on (nearly) vertical walls.