Isotope - Chain Reactor

Drop an orb, watch the board explode. Isotope is a snappy, free-to-play take on the classic chain-reaction strategy game — turn-based, beautifully drawn, and built to be played in two-minute bursts on the bus or two-hour sessions on the couch. The rules are simple. The strategy is not. Tap any empty cell, or stack on a cell you already own, to drop one orb. When a cell hits its critical mass — 2 for corners, 3 for edges, 4 for the middle — it FISSIONS. The orbs scatter to every neighbour, instantly capturing whatever was there. Daisy-chain enough explosions and the entire board can flip in a single turn. Last colour standing wins. — GAME MODES — DUEL — One-on-one against seven distinct AI opponents, each with a different playstyle. Start gentle with Sparky on a 4×4 board, work your way up to Nova on the 7×9 grid. Beat each AI with 1, 2, AND 3 cycling colours to fully master it. WEEKLY CHALLENGE — A handcrafted puzzle every week. Solve it in the exact number of moves to claim the coin reward — Beginner (50 coins) up to Master tier (250 coins). ENDLESS — Random board, random difficulty, every wave. How far can you push the cascade before the AI corners you? TRAINER — Both sides played by you, on any board size up to the 9×7 giant. No score, no AI — just pure positional study. — FEATURES — • Six visually distinct elements — Uranium, Thorium, Radium, Radon, Polonium, Plutonium — purely cosmetic, mechanically identical • 1-, 2-, or 3-colour cycling play at higher difficulties for an extra strategic layer • Boosters: Hint (50 coins), Undo (75 coins), Skip an AI turn (100 coins) • Daily login bonus + weekly challenge rewards + watch-to-earn coins • Looping ambient soundtrack and a satisfying blast SFX for every cascade • Haptic feedback that scales with cascade depth • Music, Sound FX, Haptics, and Volume all controllable in Settings — PRIVACY-FIRST — • 100% playable offline • No account required — no sign-up, no login, no email • Save data is stored on your device only • Personalised ads only with your explicit App Tracking Transparency consent — FREE-TO-PLAY DETAILS — Isotope is free to download and play. Optional rewarded ads grant in-game coins; an optional one-time "Remove Ads" purchase disables them entirely. Coins are an in-game currency only — they have no real-world value and can't be exchanged for cash. Built by Genesis Solutions.