Sunfallow

The world

The landscape is the main character.

Every world starts from a seed: a number or any text. The same seed and size always give the same world, down to the last river. The sea surrounds the land, and the world is finite.

Continents, mountain chains and island groups are shaped first, then climate, then rivers: water flows downhill, merges into larger rivers, fills lakes and ends in the sea. Settlements, roads and ruins come last.

The world map window showing discovered settlements as round islands with names, and explanatory text below.
The world map: only explored land is drawn.Gameplay captureCaptured in version 0.9.1, 30 October 2026

Biome atlas

25 surface biomes. Each page lists what the game data says lives and grows there. The pictures are real captures; where none exists, it says so.

Filter by climate

  • Green alpine meadow with a lone pine, bounded by the sea on the left.

    Alpine Meadows

    Mountain meadows with edelweiss, heather and pines.

    • Cold
    • Temperate
  • Large dark trees of an ancient forest at a coast.

    Ancient Forest

    Huge ancient trees, ferns, mossy boulders and glowcaps.

    • Temperate
    • Wet
  • No capture yet

    Ash Wastes

    Basalt, coal and ruby geodes under grey ash.

    • Hot
    • Dry
  • A forest with orange maple trees and leaf litter next to a bay.

    Autumn Forest

    A maple forest with fallen logs and mushrooms.

    • Temperate
    • Wet
  • No capture yet

    Badlands

    Red sandstone and rock spires with dry shrubs and a little gold.

    • Hot
    • Dry
  • A light birch forest with a winding river and a sheep.

    Birch Forest

    A light forest of birches with flowers and mushrooms.

    • Temperate
  • No capture yet

    Coast

    Sandy shores with palms, reeds and clay where land meets sea.

    • Warm
    • Dry
  • No capture yet

    Deep Ocean

    The darkest sea, far from any coast.

    • Water
  • Sand dunes with ripple patterns and a dirt track crossing the desert.

    Desert

    Sand dunes with cacti, dry shrubs and sandstone.

    • Hot
    • Dry
  • A green meadow with flowers and sunflowers, a fence and a wheat field at the top, a sandy shore at the right.

    Flower Meadows

    Meadows of poppies, cornflowers, lavender and sunflowers.

    • Temperate
  • A dense oak and pine forest with a wooden watchtower and mushrooms between the trees.

    Forest

    Dense oak forest with pine, ferns, mushrooms and berries.

    • Temperate
    • Wet
  • Pale blue ice with cracks, ice blocks and an amethyst geode; dark rock at the right edge.

    Glacier

    Cracked ice with ice blocks, frozen boulders and amethyst geodes.

    • Polar
    • Cold
  • Dense jungle with dark broad trees and palms next to a river.

    Jungle

    Thick jungle trees, palms, ferns and glowing glowcaps.

    • Hot
    • Wet
  • No capture yet

    Mangrove

    Mangrove trees in shallow water with reeds and clay.

    • Wet
    • Warm
  • Grey cracked rock with boulders and a few pines.

    Mountains

    Bare rock with coal, copper, iron and gold, and a few pines.

    • Cold
    • Dry
  • No capture yet

    Oasis

    Palms, reeds and meadow in the middle of the dry land.

    • Hot
    • Wet
  • No capture yet

    Ocean

    Open sea with depth bands that surrounds every continent.

    • Water
  • A grassland with flowers, a fence and a small red-roofed hut at a bay.

    Plains

    Open grassland with oaks, bushes, wild carrots and flax.

    • Temperate
  • Yellow grassland with scattered acacia trees and a river on the right.

    Savanna

    Dry yellow grass with scattered acacias.

    • Warm
    • Dry
  • Snow-covered ground with snowy pines and a patch of thawed grass.

    Snow Forest

    Pines under snow, snowy bushes and frostbloom.

    • Polar
    • Cold
  • Dark green wetland with willows, reeds and mushrooms next to open water.

    Swamp

    Willows, reeds, brown mushrooms and clay by dark water.

    • Wet
    • Warm
  • No capture yet

    Tropical Islands

    Palm islands with jungle bushes and sandstone.

    • Hot
    • Wet
  • Grey-green tundra with small rocks and a river; a wolf stands at the bottom right.

    Tundra

    Cold grassland with frozen boulders, snowy bushes and frostbloom.

    • Cold
    • Dry
  • Black basalt ground with dead trees and red crystals.

    Volcanic Lands

    Black basalt, coal, iron, ruby geodes and fire lilies.

    • Hot
    • Dry

This is a list, not a map of a real world. A real world map appears in the game itself.

Below the surface

Cave mouths and mine entrances lead into the Hollows and the Deep Caverns. Dungeons, abandoned mines and ruins wait there, along with ore, crystals and hostile creatures. These layers exist in the internal build.

In the internal build
  • A lower hall with a magma creature, the Magma Matriarch, a boss health bar at the top.

    Deep Caverns

    The layer below the Hollows with lava, ember imps and magma beetles.

    • Underground
    • Hot
  • A stone hall with torches and a large guardian, the Stone Warden, and its name above it.

    Dungeon Halls

    Built halls with torches, chests and a boss.

    • Underground
  • A lower hall with a magma creature, the Magma Matriarch, a boss health bar at the top.

    Ember Citadel

    A fiery stronghold with ember imps and magma beetles.

    • Underground
    • Hot
  • A dark cave with glowing blue crystals and green moss, lit only by a small area around the player.

    The Hollows

    The first underground layer: cave chambers, corridors, lakes, ore and glowing crystals.

    • Underground

Weather and seasons

Weather is a fixed function of seed and time: rain, storms with lightning and thunder, snow, morning fog and sandstorms in deserts, local to a biome. Seasons (spring, summer, autumn, winter) last 3, 6 or 10 days, or can be switched off in the world rules.

Both exist in the internal build since version 0.4.0. They are not part of anything you can download.

In the internal buildIn the internal build

The village in rain: the picture is slightly darkened and tinted.
Rain over Dunmere (spring, day 3).Gameplay captureStaged sceneCaptured in version 0.9.1, 30 October 2026
The village field and paths under snow in winter.
Winter in Dunmere (season set by the screenshot tool).Gameplay captureStaged sceneCaptured in version 0.9.1, 30 October 2026

Felling and regrowth

A felled tree becomes a stump, then a sapling, then a tree again. Animal numbers follow the forest that remains, and herds move away from cleared land. The systems are simple and not a scientific ecosystem model.

Things to find

Camps, ruins, shrines, watchtowers and caches are placed by the generator with fixed loot tables. Watchtowers reveal part of the map, and shrines grant a daily blessing.

In the internal build