Massive March

A first-person cooperative campaign with no combat, no health bar and no quest markers. You — on your own, or with up to eleven friends — land on a coastline of granite headlands and gum-tree gullies, scattered with enormous toy-coloured structures somebody left behind, and work out what any of it is for. Voice and text are both spatial: they fade with distance, muffle through a ridge and stop dead at a soundproof booth wall — so the sealed room holding the answer is a room whose occupant cannot simply tell you. Carry one thing in your hands, two on your belt, four more in a backpack you cannot open yourself. Solve installations to produce red rounds, walk them to the towers, and let the keys they hand back open the cart line, the ridge road and finally the White Gate. The sun sets, and the island gets genuinely dark.