Astro Merge: The Cosmogony — a free Greek myth drop-and-merge puzzle
Astro Merge: The Cosmogony is a free browser-based drop-and-merge physics puzzle built on Greek creation myth. Erebus, the primordial dark, unstitched the ladder of creation and shook its fragments into the Well of Night — then took the moon-maiden Artemis with him. You are Aster, apprentice of the Titaness Phoebe, and your whole world is one well, one queue of falling fragments, and one sentence of arithmetic: two of a kind become one rung higher.
Eleven rungs separate a Spark from a Cosmos. You are never handed anything above the fourth rung, so everything higher has to be built out of what you were given, one fusion at a time — while the heap grows, the well narrows in the later acts, and a glowing chaos line waits near the rim for the first careless stack.
How to play
- Aim. Move the mouse, or drag your finger across the well, to choose the column the next fragment falls down. A dashed guide and a ghost ring show where it will land; if the landing will fuse with a matching fragment, the ring turns green and the partner pulses.
- Drop. Click, tap, or simply release the drag.
- Fuse. Two fragments of the same kind that touch become the next rung, and the new fragment appears exactly between them. Fusions that happen within a second of each other chain into a combo worth up to ×5, which is where the big scores come from.
- Guard the chaos line. If a settled fragment stays above the glowing line for two seconds, the well gives way. The bar at the top of the well shows how much of that grace you have already spent.
- Read the queue. The next fragment is previewed in the ring at the top right of the well. The mistake that ends runs is always made with the fragment you are not holding.
- Seal, or gamble. As soon as the chapter goal is met you may seal the chapter and keep it. Staying in costs fragments and risks the line, but it is the only way to reach the three-star par.
Controls
| Input | Action |
|---|---|
| Move the pointer / drag | Aim the next drop |
| Click / tap / release | Drop the fragment |
| ← → or A D | Nudge the aim by one fragment-width |
| Space / Enter | Drop |
| U / Z | Titan's Hand — take the last fragment back |
| E / H | Oracle's Eye — simulate the shot before you take it |
| X | Earthshaker — shake the heap into a flatter shape |
| R / Esc | Restart the chapter / pause |
| S | Mute or unmute the synthesised well |
The eleven rungs of creation
| # | Fragment | Greek | What it is |
|---|---|---|---|
| 1 | Spark | Σπινθήρ | the first thing that was ever lit, and the only thing you can always be given |
| 2 | Stone | Πέτρος | two sparks agreeing to stay in one place |
| 3 | Ember | Ἄνθραξ | heat that has learned to wait |
| 4 | Dew | Δρόσος | water, and therefore memory |
| 5 | Bloom | Ἄνθος | the first thing in the world that wanted to grow |
| 6 | Crystal | Κρύσταλλος | order — the reason a stone remembers being a spark |
| 7 | Comet | Κομήτης | the dark, wounded and beautiful |
| 8 | Star | Ἀστήρ | a promise that the dark has an edge |
| 9 | Moon | Σελήνη | Artemis's own light, and the key to her chains |
| 10 | Sun | Ἥλιος | an argument the dark cannot win |
| 11 | Cosmos | Κόσμος | the finished ladder — and, if you ever collide two of them, the Crown of Ananke |
The rules, exactly
| Situation | What happens |
|---|---|
| Two fragments of the same kind touch | They fuse into one fragment of the next rung, released at the point of contact |
| Two Cosmos touch | They annihilate into the Crown of Ananke: nothing is left on the board and the points are the largest in the game |
| A void shard touches anything but a void shard | Nothing. It is a physical obstacle and a permanent hole in your board |
| Two void shards touch | They cancel each other out and vanish, which is the only way to clear the well of them |
| A fragment settles above the chaos line | A two-second countdown starts; drop the heap back below and it resets. Run out and the chapter is lost |
| Your fragments run out with the goal unmet | The chapter is lost — you may retry it as often as you like, and its sequence is fixed, so the second attempt is a plan rather than a lottery |
| Nyx's veil falls on a drop | The guide line and the landing ghost disappear for that one drop. The physics is unchanged; only your information is |
The four acts of the campaign
| Act | Chapters | What it teaches |
|---|---|---|
| I · The First Spark | 1–8 | Sparks, stones, embers and dew; the habit of dropping the biggest fragment first and never stacking in a column |
| II · The Ladder of Creation | 9–16 | Crystals and comets in a narrower well — and Erebus's void shards, which must be buried low or paired off |
| III · The Veil of Nyx | 17–24 | Drops you cannot see coming, and the first chapters that ask for a Star and then for the Moon itself |
| IV · The Crown of Ananke | 25–30 | A cracked rim, comets as your raw material, and a final chapter that asks for the Sun |
Campaign versus the endless well
| Campaign | Endless — the open well | |
|---|---|---|
| Structure | Thirty chapters in four acts, each with its own goal, fragment budget and measured par | One well that never fills, played until the heap crosses the line |
| Difficulty | Ramps from three rungs of fragments to six, with void shards and Nyx's veil arriving in Acts II and III | Grows with you: the queue gets heavier every thirty fragments and the dark slips in more often |
| Tools | Three undos, three Oracle's Eyes and two Earthshakers per chapter | The same, once per run — spend them or lose them |
| What you chase | Stars: one for the goal, three for the measured par line | One number, kept on your device, that is only ever beaten by playing better |
Why par is a number you can trust
Plenty of puzzle games invent a three-star line. This one measures it. Every chapter ships with a fixed sequence of fragments, and that sequence was handed to the same reference oracle that runs inside the page: it plays the chapter to the end under exactly the rules you face — void shards, chain fusions, the chaos line, the same physics — and the score it actually reached becomes par. That is why chapter one asks for 65 points and the last chapter asks for 1871, and why the Oracle's Eye tool can tell you the truth: it is not an animation, it is the simulation, run forward on a copy of your well before you commit.
Strategy that actually works
- Keep two flat columns. A well that is flat everywhere can absorb anything. One tall tower and a Bloom in the queue is a lost run.
- Drop big first. The largest fragment you are given should go down early, while there is still room to build around it. Save the small ones for the gaps.
- Bury the void shards. A void shard is a hole in your board forever. Put it against a wall at the bottom of the well, not in the middle where the ladder needs to grow.
- Chain on purpose. A fusion that lands next to a matching fragment fuses again a fraction of a second later, and the combo multiplier is where the par lines come from. Set up pairs before you need them.
- Seal when the goal is met, unless you need stars. Nothing is lost by leaving early. The book of the game is written by the runs you did not throw away.
Technical notes
The whole game is one self-contained page: no third-party scripts, no trackers, and no network calls after the first load. Every pixel is drawn in code on an HTML5 canvas — the engraved basin, the eleven sigils, the nebula and the rotating zodiac wheel behind the well — and the layout is recomputed from scratch on every resize, so the same well is playable on a 320-pixel phone and on a desktop monitor.
The simulation is a deterministic fixed-timestep circle solver: gravity, positional correction and restitution resolved 120 times a second, with no Math.random() anywhere in the physics. Each chapter's fragment sequence is dealt from its own seed, which is why the same chapter is the same puzzle on every device, why retries are a plan rather than a lottery, and why par could be measured offline and baked into the level data as a number instead of a guess.
Progress is stored locally in your browser under astromerge.save.v1: unlocked chapters, stars, best scores, your endless best and your sound preference. Nothing is uploaded, because there is no server.
Frequently asked questions
Is Astro Merge: The Cosmogony free to play?
Yes. Astro Merge is completely free, needs no account, no download and no plugin, and it never asks for payment. It runs in any modern browser on desktop, tablet or phone, and your progress is stored only in your own browser.
How do you play Astro Merge?
Move the pointer or your finger to choose where the next fragment should fall, then click, tap or release to drop it. Two fragments of the same kind touch and fuse into the next rung of the ladder: two Sparks make a Stone, two Stones make an Ember, and so on up to the Cosmos. The run ends only if a settled fragment is left above the glowing chaos line for two full seconds.
What happens if the heap crosses the chaos line?
Nothing at first. A fragment has to settle with its top above the glowing line and stay there for two seconds before the well gives way, and the timer resets the moment the heap drops back down. The bar on the screen shows how much of that grace period you have used, so a risky stack is always a visible risk rather than a surprise.
What are void shards and what is Nyx's veil?
Void shards are Erebus's own fragments. From Act II he slips them into your queue, and they fuse with nothing except another void shard, so they are pure obstruction that has to be buried low or paired off. Nyx's veil is a screen effect from Act III: on certain drops the night-goddess hides the guide line and the landing ghost, so you have to read the heap itself before you commit.
How many chapters are there and how hard do they get?
Thirty chapters in four acts. Act I hands you the three smallest fragments and asks for a handful of merges; by Act IV you are given Comets and asked to forge the Moon and finally the Sun, with void shards in the queue and the veil across the well. Every par line was measured before shipping: the reference oracle in the page played each chapter under the same rules you face and its score is the three-star target.
Can I play Astro Merge on a phone?
Yes, and the layout is built for it. The well, the queue, the goal meter and the three tools all re-flow to the screen you are on, a drag aims and a release drops, and the whole game is one page with no images to download, so it starts instantly on a mobile connection.