A puzzle you can hear

Why we made it

Chain reactions are a joy to watch, but most chain-reaction games are a race: tap fast and hope. Carillon slows the idea down. Rings are exact circles that grow at one speed, and holding a dot shows exactly what its ring will pop, so the puzzle is reading the field, never guessing.

A carillon is a set of bells, usually in a tower, played from a keyboard. The name fits: every pop rings a note, and a full clear sounds like a short song. We wanted a game that respects your time and attention, with no energy bars, no countdowns and nothing that interrupts a puzzle.

How it sounds

A dot's colour is its note in the C major pentatonic scale, C, D, E, G and A, and its size is the octave: big dots are low, normal dots sit in the middle, and small dots are high. A pentatonic scale has no semitones and no tritone, the two intervals that clash, so a chain in any order, with several pops at once, still sounds like music.

The tone is a marimba synthesised in code, with a short reverb baked into every note, so it sounds the same on a phone and in a browser. The win sound runs up the scale and lands on the home note.

How it is built

Every level is grown by a generator and then proven by a solver that finds the fewest taps that clear it. That number sets the taps a level allows and how the stars are scored. The levels are ordered by a measured difficulty so each one is at least as hard as the one before, and no two are the same, even turned, mirrored or with the answer in the same place. The tests check all of that again on every build.

The art and every sound are made in code, not bought or downloaded. The game is written in GDScript with the Godot Engine, and the same code runs on Android and in your browser.

How it stays free

Carillon is free, on Android and in your browser. The Android app has a few ads, placed so they never touch a puzzle: a banner at the bottom of the level list and below the field, an occasional ad between levels once you have solved the first dozen, and a short video you can choose to watch for an extra hint. Nothing ever appears over the field, no full-screen ad interrupts a chain, and the web version never shows ads.

If you would rather play without them, the Supporter pack is a one-time purchase in the app. It turns the ads off for good, makes every hint free, and helps pay for the next game.