Sediment

Sediment is a pixel-physics sandbox built from 50 materials. You shape a world where sand pours and settles, water floods and freezes, lava cools into stone, and acid eats what it touches. Materials interact through simulated rules for density, temperature, burning and explosions.

Material interactions

Density determines how materials settle: gold lies beneath everything else, so washing ore into a basin leaves the gold at the bottom as its own layer. Temperature transfers only to what a material touches. Pouring water onto lava makes stone and a flash of steam, while heat reaching only two cells through a wall means a furnace needs to be a chamber with fuel inside rather than a fire beside it.

Some materials burn or explode. Sulphur over cinder makes gunpowder, which becomes hot, expanding gas that ignites what it reaches rather than simply burning faster. A spirit fuse in a trench carries flame to the far end.

Simulated worlds

The world consists entirely of cells, not particles layered over an image. Each rule is an exchange between neighbouring cells, and mass is never accidentally created or lost.

Create and share

You can make materials in the in-game editor by defining properties such as density, phase, what a material melts into and what it absorbs. Materials are JSON entries, and you can publish a pack to the Workshop for it to appear in another player's palette. You can also save and publish levels, then subscribe to other players' levels. Each level lists the packs it requires, so shared worlds do not open as grey stone in place of their materials.

Lessons and tasks

• Nine lessons that teach through doing rather than reading
• Twenty tasks with goals
• Picture: turn an image on your disk into materials