Cutting the stone free of the hill…
No ads in Sisyphus Unbound — just you, the stone and thirty chapters of the pit
Play Sisyphus Unbound: The Stones That Freed Persephone — a free 3D ball-rolling puzzle in your browser
A free browser 3D ball-rolling puzzle in the Greek underworld. Roll the stone down 30 hand-carved chapters, dodge sliders, hammers, bombs and gales, and break six seals to free Persephone.
Sisyphus Unbound is a free browser-based 3D ball-rolling physics puzzle built on Greek myth. Hades never chained Sisyphus to that boulder as a punishment — he bound the six seals of Persephone's prison to a single bronze stone, on the reasoning that a stone which must be pushed uphill for ever is a stone nobody ever gets to push anywhere else. You are Hermes. You have stolen the stone off the top of the hill, and you have thirty chapters of the pit to steer it down.
What makes it more than a marble run is that the stone has mass and the floor has opinions. Basalt is neutral, ice keeps every bit of speed you arrive with, tar stops the stone dead, spring pads throw it over gaps, crumbling flagstones are on a timer the moment you touch them, portcullises answer to bronze floor plates, and ferry plates slide and carry you across. On top of that sit sliders, spinners, swinging hammers, armed bombs and gale corridors — all of them periodic, none of them out-runnable. Thirty hand-carved chapters across four acts, an endless descent that goes deeper until the pit keeps the stone, and every chapter proved winnable by a reference rider before it was allowed to ship.
How to play
- Steer, do not push. Touch or click anywhere and drag: the stone accelerates away from your finger or cursor. A short drag is a nudge; a long drag is everything the ground allows. There is no jump button and no brake — the stone only ever goes where the floor and the slope let it.
- Read the ground before you commit. Basalt is neutral. Ice has almost no grip and will carry you straight past the turn you wanted. Tar grips hard and stops the stone dead, which is a gift at the bottom of a drop and fatal in the middle of a crossing. A spring pad throws you over whatever you cannot roll across.
- Crumbling flagstones are on a timer. The moment the stone touches one it starts to sag, and a breath later it is gone. Cross in one movement or do not step on it at all.
- Portcullises need a floor plate. Roll the stone over a bronze plate and every gate ahead grinds up. They are shortcuts, never the only way down: the pit is always passable with every gate shut, and the game proves it chapter by chapter.
- Wait for the trap gallery. Sliders sweep back and forth, spinners rotate around a hub, hammers swing on a long arm, bombs arm the instant the stone touches them, and gales shove you sideways. They run on fixed cycles and none of them can be out-sprinted. Standing still and watching one full cycle is not wasted time — it is the move.
- Light the cold fires. A blue flame on the floor is a checkpoint. Light it and a fall sends the stone back there instead of to the top of the chapter.
- Reach the well. The shaft of light at the bottom is the end of the chapter. Three stones per chapter, three embers for a perfect run, and par is a measured time rather than an invented one.
Controls
| Input | Action |
|---|---|
| Touch & drag (phone, tablet) | Steer — the stone accelerates away from where you touched down |
| Move the mouse (desktop) | Steer — the stone accelerates away from the cursor |
| Click & drag (desktop) | Steer from the point you pressed, useful for long committed pushes |
| ↑ ↓ ← → or WASD | Steer on the eight points of the compass |
| R | Restart the chapter |
| Esc or P | Pause — which freezes the traps as well as the stone |
The floor, exactly
| Surface | What the stone does |
|---|---|
| Basalt (grey) | Neutral grip — the reference surface everything else is measured against |
| Ice (pale blue) | Almost no friction, so the stone keeps nearly all of the speed it arrived with. Ice is a delivery system and a hazard at once |
| Tar (black pool) | Heavy friction. Arrives fast, leaves slow — a brake you can aim at, and a trap if you have to cross it |
| Spring pad | Launches the stone upward on contact, clearing gaps and traps a roll cannot cross |
| Crumbling flagstone | Sags the instant the stone touches it and falls away a moment later. One crossing per flagstone |
| Floor plate (bronze) | Opens every portcullis ahead when the stone rolls over it. A shortcut, never the only route |
| Ferry plate (sliding) | Slides along its axis and carries whichever stone is standing on it — the only way across some crossings |
| Cold fire (blue flame) | A checkpoint. Falls return the stone here rather than to the top |
| Well (shaft of light) | The exit. The stone is pulled in and the chapter is over |
The traps, exactly
| Trap | Behaviour | How to survive it |
|---|---|---|
| Slider | Sweeps back and forth across a lane on a fixed period and shoves the stone sideways on contact | Cross on the far half of its sweep, or on the beat when it is travelling away |
| Spinner | Rotates a bar around a hub; contact throws the stone tangentially | Pass when the bar is parallel to your direction of travel |
| Swinging hammer | Swings a head on a long arm through an arc, knocking the stone back down the corridor | Wait out one full arc; the safe window is when the head is climbing, not falling |
| Armed bomb | Arms on contact, then detonates once, shoving the stone radially and shaking the level | Touch it deliberately early, or never touch it. There is no third option |
| Gale corridor | A rectangular region of the pit that pushes the stone sideways while it is inside | Enter it already angled into the wind — the wind is a constant force, not a nudge |
| Portcullis | Solid until a floor plate is pressed, then sinks into the ground | Never required; the pit is always passable with all of them down |
The four acts of the campaign
| Act | Chapters | What it teaches |
|---|---|---|
| I · The Ashen Foothills | 1–8 | Ash to the ankles and the first sky-wells: how the stone carries speed, and why ice and tar are two different kinds of danger |
| II · The Bronze Terraces | 9–16 | Hammered bronze and locks that were never meant to turn — portcullis plates, the first spinners, and the first checkpoints worth lighting |
| III · The Winds of Tartarus | 17–24 | The pit breathes and the breath is a wall: gale corridors, ferry crossings, hammers, and bombs on the only road down |
| IV · The Gates of Hades | 25–30 | Six seals, one goddess, no more favours — every mechanic at once on eleven-wide chapters |
Campaign versus the endless descent
| Campaign | Endless — the descent | |
|---|---|---|
| Structure | Thirty hand-carved chapters in four acts, each with a measured par time | Generated chapters that get deeper and nastier until the pit keeps the stone |
| Difficulty | Seven to eleven squares wide, up to eight traps, two winds, one to three embers | Starts around chapter six and climbs: more traps, more wind, more floor you cannot trust |
| Fairness | Every chapter was proved winnable by a reference rider before it was allowed to ship | Every descent is generated, proved winnable, and priced for par before you are shown it |
| What you chase | Stars and best times, one row per chapter | A single depth number, kept on your device |
Why par is a number you can trust
Most games invent a three-star target. This one measures it. Every chapter was played by the same reference rider the game ships with — an autonomous stone that runs the level on pure pursuit, at eight different trap phases — and par is the slower of two numbers: the fastest run plus a third, or the median run plus a tenth. The first keeps par honest on a chapter whose traps always line up the same way; the second keeps it honest on a chapter where arriving at the wrong moment costs fifteen seconds. What proves a level and what plays it can never drift, because they are the same code.
Strategy that actually works
- Stop steering before the turn, not during it. The stone decelerates slowly and turns slowly. The two seconds after a corner are where chapters are lost, and releasing the stick early is the whole fix.
- Use tar as a brake, not as an obstacle. A tar pool at the bottom of a drop is a gift; the same pool in the middle of a crossing is the reason you fell.
- Ice is transport. Get onto ice pointed the right way and you cross half the chapter without spending anything. Get onto ice pointed the wrong way and you find out how much of the pit has no railing.
- Light every cold fire you pass, even out of the way. A checkpoint costs three seconds and saves a whole attempt.
- Do not treat the gale as a nudge. Wind here is a constant acceleration. Fight it head-on and you lose the whole width of the corridor; enter already angled into it and you cross in a straight line.
- Watch the trap for a full cycle before you move. Every trap in the pit is periodic and none of them change their period. One cycle of standing still buys you the whole chapter.
- Bank the embers on an easy chapter. Three stars needs every ember and no falls, and on the chapter where you finally beat par you will want them already collected.
Technical notes
The whole game is one self-contained page: no third-party scripts, no trackers, and no network calls after load. The stone, the pit, the weather and the traps are all drawn in software on an HTML5 canvas — a real 3D camera with perspective projection, depth sorting and distance haze — the sound is synthesized in WebAudio, and the layout is recomputed on every resize, so the same chapter plays on a 320-pixel phone and on a desktop monitor.
Physics runs on a fixed timestep of 1/120 of a second and the live simulation contains no random numbers at all: a run is a pure function of the chapter, the trap phase and your inputs. That is what lets the generator carve a route, run a breadth-first check that no portcullis is ever a chokepoint, hand the level to the reference rider at eight trap phases, and only then bake the layout and its par into the level data. Endless descents are carved, proved and priced the same way at runtime, which is why the pit can never hand you a chapter that cannot be won. Progress, stars and best times are stored locally under sisyphusunbound.save.v1; nothing is uploaded, because there is no server.
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Sisyphus Unbound: The Stones That Freed Persephone — frequently asked questions
What is Sisyphus Unbound: The Stones That Freed Persephone?
It is a free browser 3D ball-rolling puzzle built on Greek myth. Every chapter is a stretch of the underworld you steer a bronze stone down: a start pad at the top, a well at the bottom, and ice shelves, tar pits, spring pads, crumbling flagstones, portcullises, moving ferry plates and trap galleries in between. Thirty hand-carved chapters across four acts, plus an endless descent that goes deeper until the pit finally keeps the stone.
How do you control the stone?
Drag anywhere on the screen — the stone accelerates away from your finger, so a short drag is a nudge and a long one is full speed. On a desktop you can also just move the mouse: the stone accelerates away from the cursor. The arrow keys and W A S D work as well. There is no jump button and no brake: the stone only ever goes where the floor and the slope let it, which is why the chapters are about reading the ground ahead rather than about reflexes.
Why does the stone only stop falling when it reaches the well at the bottom?
Because the well is the seal. Each chapter ends at a shaft of light coming up from below, and the stone has to be delivered into it. Everything between the start pad and the well is the actual puzzle: ice carries you far too fast to steer, tar grips the stone and stops it dead, spring pads throw it over gaps, crumbling flagstones fall away a moment after the stone touches them, and the trap gallery has to be crossed while it is in the right part of its cycle.
What happens when the stone falls off the edge?
You get the stone back at the last checkpoint you lit, or at the top of the chapter if you have not lit one. Falling costs a stone, and you begin each chapter with three. Lose all three and the chapter restarts — but falling also costs you the clean-run star, because one of the three stars requires reaching the well with no fallbacks at all.
What does the par time on each chapter mean?
It is a measured time, not an invented one. Every chapter was played by a reference rider at eight different trap phases, and par is the slower of two numbers: the fastest run plus a third, or the median run plus a tenth. The first keeps par honest on a chapter whose traps always line up the same way; the second keeps it honest on a chapter where arriving at the wrong moment costs fifteen seconds. Par is never a time nobody can reach. Reaching the well inside par, with no fallbacks and every ember collected, is the three-star run.
Does it work on a phone, and does it need a download?
There is no download, no account and no install: it is one HTML5 page that runs in the browser on desktop, tablet and phone, including a 320-pixel screen. On a phone the whole screen is a joystick — touch anywhere and drag. On a desktop the cursor steers. Progress, stars and best times are kept in your own browser.