Steam Next Fest · Out 3 NovComing 3 November

Atom By Atom

Build a factory around a black hole. Extract elements, route atoms through Matter Tubes, bond them with valence-driven chemistry, and scale precise molecular production lines atom by atom.

Windows · Mac · Linux · Browser

Trailer

You start with hydrogen. A cloud of it drifts past; an extractor pulls atoms out; a tube carries them to the black hole, which is hungry, specific, and never satisfied for long.

Then it asks for oxygen. Then water — which means two hydrogens and an oxygen have to arrive at a bonder at the same moment, in the right proportion, without either line backing up. Then hydrogen peroxide. Every contract you complete unlocks the next element, the next machine, and a slightly less forgiving molecule.

What you build

  • Extractors pull single atoms from element clouds that drift through the map.
  • Matter Tubes carry atoms. They do not merge, they do not sort, and they back up when the next machine is busy — which is most of the game.
  • Dividers split a flow so one extractor can feed two bonders.
  • Bonders join atoms into molecules using real valence rules. A bonder fed the wrong ratio simply waits.
  • Wormholes let you skip the geometry when the geometry is the problem.

Why it’s interesting

Chemistry gives the game a rule set it didn’t have to invent. Water is H₂O because it is; the puzzle is delivering exactly that, at rate, forever. Later contracts — polymerisation, cyclisation — turn a tidy little line into something that has to be planned.

Demo

The free demo covers the hydrogen tutorial and the first four contracts (H₂, O₂, H₂O, H₂O₂), plus a sandbox mode that keeps going after the last one. It runs in the browser and on Windows, Mac and Linux, and saves can be exported as a code and brought into the full game.

The demo will be live during Steam Next Fest, 19–26 October. Full release on Steam is 3 November 2026.

Screenshots

Atom By Atom screenshot 1Atom By Atom screenshot 2Atom By Atom screenshot 3Atom By Atom screenshot 4Atom By Atom screenshot 5Atom By Atom screenshot 6Atom By Atom screenshot 7Atom By Atom screenshot 8Atom By Atom screenshot 9Atom By Atom screenshot 10

News about Atom By Atom

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15 September 2026

Thank you for 100 wishlists

The first hundred wishlists for Atom By Atom are in. Thank you to everyone who played the demo, sent feedback, or added the game to their list.