SpaceChem

You take the role of a reactor engineer for SpaceChem, building systems that transform raw materials into chemical products for frontier colonies.

Each puzzle asks you to arrange commands on reactor grids so moving manipulators can grab, move, rotate, bond, or split atoms. Coordinate their routes and timing to produce the required molecules, often within limited space.

The campaign progresses through more than fifty puzzles, introducing increasingly complex production challenges and encounters with threats to SpaceChem. You can also refine working designs by reducing their cycles, instructions, or reactor use.

Players who enjoy SpaceChem often praise its demanding logic and programming-style puzzles, the freedom to devise their own solutions, and the satisfaction of seeing a carefully planned reactor run correctly. Many also like optimizing designs after solving them. Some find the challenge absorbing and rewarding, while others describe it as too difficult or demanding.