Your plane crashed on a forested mountain island. Rescue only comes if you repair the radio at the mountain tower, and you have 7 days.
Follow the mission list: gather supplies, build a campfire and shelter, find 3 radio parts in the ancient ruins, then survive until the helicopter arrives. Wolves hunt at night. A river runs east of the crash site.
Controls: WASD move, mouse look, Shift sprint, V switch third/first person, mouse wheel zoom (third person), E interact (pick up, drink, chop trees), click or F attack, G throw a stone (makes ripples on water). Best on desktop.