Minecraft

A world that goes on in every direction, generated from a seed and streamed in as you walk. Punch a tree for wood, turn it into planks, sticks and a pickaxe, and get stone — then be underground or behind a door before dark, because monsters spawn on any block with no light on it and after sunset most of the world qualifies. A day is twenty minutes. Hardness, tool tiers, ore depths, hunger and saturation all follow the numbers the real game uses, so diamonds really are best at y = −58. Every texture, sound and model here is generated in code rather than borrowed.