Slide atoms. Beat the decay.

A sliding puzzle with real chemistry inside. Bond atoms into real molecules and stay one move ahead of radioactive decay across 100 handcrafted levels in ten worlds.

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Levels: 100
Worlds: 10
Achievements: 50

Isotope desert level where hydrogen and nitrogen atoms slide across the board to build ammonia

How it plays

Real science, playful rules.

Carbon-14 turns into nitrogen, tritium into helium. Isotope turns real radioactive decay into a simple question on every move: act now, or wait?

Slide and bond

Every swipe sends a molecule gliding until something stops it, and atoms bond the moment they touch.

Beat the decay

Every move ticks every radioactive clock. Build before an atom decays, or wait for it to change.

Real chemistry

Each radioactive atom is a real isotope. Build water, ammonia, methane, and over a hundred real compounds.

Ten worlds

100 handcrafted levels, from a desert oasis to a laboratory, a volcano, a reactor, and a star forge.

Isotope laboratory level with a decay counter showing four moves left to build chloramine

Build it before it decays.

Each world adds a new idea to the board, so the puzzles keep changing as you travel from the desert to the heart of a star.

Blast through cracked walls with unstable molecules
Melt frost and quench hot floors
Ride ocean currents and hold gates on pressure plates
Split uranium and start chain reactions
Tunnel through barriers and move entangled atoms

Fair and solvable.

Every level is proven solvable by a solver, and par is the true minimum number of moves. Match it for three stars. If you get stuck, a hint shows the next step of a verified solution.

50 achievements with Game Center, and a chemical catalog of every compound you discover.

Isotope supernova level in the star forge world with an exploding star behind the board

Play it your way.

Isotope ocean level played in landscape with currents pushing atoms across the board

Play in portrait or landscape. No ads, no timers, no energy systems, and it plays fully offline. The first world of 10 levels is free, and one purchase unlocks all ten worlds and 100 levels.

Coming 9 November 2026

Isotope launches on the App Store on 9 November 2026.

One purchase plays on iPhone, iPad, Mac, and Apple TV. The App Store link will be added here on launch day. Until then, use the contact form for questions or press inquiries.

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