The best horror games can make you shiver, but few elicit chills as well as Cryostasis: The Sleep of Reason. This is partially due to the tense atmosphere that slowly thickens as you play, inspiring a general unease that eventually escalates into full-blown panic. But it's also due to its icy Arctic setting, where the freezing air can choke your lungs and heat is the most valuable of commodities. The unforgiving blizzards of the North Pole inspire Cryostasis on multiple levels, from a heavy, deliberate pace akin to wading through drifts of snow, to multiple gameplay mechanics that keep you forever at odds with the cold. This innovative first-person adventure is not for everyone; its slow tempo will numb players seeking instant gratification, and occasional performance and stability issues may frustrate. But Cryostasis has a way of keeping you in its thrall, pushing you forward to see what frosty secrets lie ahead.