Ötzi

Ötzi is a prehistoric survival sandbox where nature is the main character.
You play as a man or a woman in prehistoric times, and your goal is to meet your body's needs: eat, drink, rest, and keep your body temperature within a comfortable range.
To do so, you can harvest resources from your environment, pick up objects off the ground and craft your own tools from them. You can pick fruit from the trees, like apples from an apple tree, or fish by the river with a spear. You can also hunt wild animals for their meat and hide, and make clothes to protect yourself from the cold and the weather.

Current features
The terrestrial ecoregions of the WWF classification, with their average temperatures, humidity and weather. Only one is playable for now: Western European broadleaf forests.

Day/night cycle and dynamic weather. Outdoor temperature depends on the time of day.

Solar radiation simulated from scientific data: at the same temperature, a clear sky and an overcast sky don't warm you the same way.

Environment procedurally generated from real temperature and humidity data tied to terrestrial coordinates.

Your body follows real physiology. Running burns calories and warms you up. Too hot? You sweat: your temperature drops, your thirst rises.

Everything comes from your environment. Pick up a stone. Pick apples from an apple tree, spear fish in the river, hunt for meat and hide, and sew clothes from it.

Build by dropping. Place objects into a building plan to raise your structures.

Wild animals.

Fishing.

The character visually reflects their thermal state, from severe hypothermia to severe hyperthermia (crossing their arms when cold, sweating when hot, skin changing color and blotching).

Multiplayer for up to 4 players.

Planned features
Ötzi aims for the most faithful simulation of Earth's nature possible. What comes next:

Seasons. Shifting temperatures, shortening days, and animal migrations true to what really happens.

The whole Earth. Choose any point on the globe to start from, and find the climate, flora and fauna that belong there.

The fauna of every ecoregion. The main animals of each region of the world, with everything that implies: what you hunt, what hunts you, what ignores you.
Farming and livestock.