Why you can trust GamesRadar+ Our experts review games, movies and tech over countless hours, so you can choose the best for you. The second is a vertical spike jutting up from the rock with some of the most technically-challenging climbing in Cairn's 15-hour runtime. When you're first introduced to Aava, she's warming up for her beginner climb. Ain't no mountain high enough(Image credit: The Game Bakers)There is beauty in Cairn's golden hour-soaked world. She's not an elite athlete, she's a puppet, and a puppet cannot climb the most dangerous mountain in the world, even with the most skilled master at her strings.