From the announcement:
In the city of Frostgate, the Northern Tribes gather each winter for feasting, celebration, and their most sacred rituals. Amongst these rituals, the Trials of Frostgate stand proudest—tests of courage, skill, and strength of arms, where the proudest and bravest warriors earn tattoos of their totemic animals. Four trials await you—and only the boldest heroes can withstand them all.
Fantasy Flight Games is proud to announce that a new adventure is now available for purchase through the Road to Legend app! Trials of Frostgate challenges you and your fellow heroes to four distinct trials, and each trial is guaranteed to test your strength and your resolve in a different way. Unlike a campaign, which progresses through a story with every new adventure, each challenge in Trials of Frostgate can be attempted multiple times as you attempt to best your scores from previous encounters!