Holly Jencka stuffs girl scout cookies into Bennett Foddy's mouth. She turns and marches on, looking at a rickety-looking rope bridge ahead of us.

"Okay," she says. "We should only do this bridge one at a time... because they have a tendency of collapsing."

We make it over one by one. If we'd tried crossing all at once the bridge would possibly give way under the combined weight of our cartoonishly large heads. It's good to have Holly here, someone who has played Peak more than the rest of us. But this kind of high-stakes multiplayer camaraderie, sometimes lovingly referred to as "friendslop", isn't actually a factor in the games created by these developers. They all make single player stuff. That means their own games feel quite different.

"That sense of isolation adds a lot to the somber mood I think a lot of climbing games have," says Holly. "This game, you don't really feel it, because you're goofing off with three other people but... I think any of the games all of us have made you get this melancholy

In Peak, you reach out your hands to grab onto surfaces. Holding left click against a wall or a tree sees you climb, but your stamina bar will drain quickly. Thankfully, players can offer an arm to hoist up a fellow climber in a difficult spot. You'll need to boost and help each other out a lot to reach the summit. It's a good thing the three game developers I have roped into this horrendous jaunt seem to be good at working together.

"I think when you talk about climbing, you're talking about a very strenuous sort of activity," says Holly, plucking fruit from a shrub growing on the side of a cliff and pocketing it for a future snack. "You're talking about this very physical thing. And giving your player character a physical body that obeys some rules of reality helps the feeling of climbing become more real in a sense, right?"

Over the course of a climb in Peak, your stamina bar will become afflicted with all sorts of clutter that reduces how much energy you have - injuries, burns, sleepiness - all reducing

"So, I assume the task is to climb that giant peak up there."

I look at the mountain and tell Bennett Foddy he is correct. The creator of Getting Over It and co-developer of Baby Steps has agreed to my unusual journalistic request. He must conquer a mountain in co-op climbing game Peak and answer my questions while doing it. And he won't be ascending alone. With us on the beach at the foot of this mountain are two other hardened developers of climbing games. Holly Jencka, lead developer of urban clambering sim White Knuckle. And Emeric Thoa, creative director of sci-fi alpine sim Cairn. They are currently rummaging through suitcases and collecting coconuts. I don't say it out loud but I have a strong feeling none of them will survive.

After messing about on the beach for a few minutes, I tell the trio they're "on their own". I'll be following, but mostly hanging back and asking questions. I want to see how three developers of climbing games will manage when faced with a mountain not of their own making. Maybe we'll uncover gems of game design wisdom along the way.