A puzzle game for iPhone, iPad and Mac
The Sleeping Engine
Wake a forgotten machine
Coming soon on theApp Store
$3.99. No ads, no in-app purchases, no account.
The game
A forgotten machine sleeps under the stones
Somewhere under a jungle temple, an old machine has been asleep for a very long time. The Sleeping Engine is a puzzle game that never tells you the rules. A source sends out signals. Gates across the chamber want them in a certain shape, colour and strength. The carved pieces in your palette change a signal as it passes, and what each one does, you find out by trying it.
Lay pipes, place the carved dreams, turn them, and watch the engine run. When every gate is fed at the same time, the chamber wakes.
How a chamber works
Source, dreams, gates
01
The source
Light leaves the source as a signal. You route it through the chamber with pipes.
02
The dreams
Carved pieces change the signal as it passes through them. Nobody tells you how. You place one, run the engine and watch.
03
The gates
Each gate wants a signal of a certain shape, colour and strength. Feed every gate at once and the chamber wakes.
- Square
- Triangle
- Circle
- Star
Square, triangle, circle or star: that is the shape a gate asks for. Colour and strength come on top.
Inside the engine
100 chambers in ten worlds
100 chambers
Ten worlds of ten chambers, each world with its own scenery and key. Every chamber brings a new dream or a new twist on one you already know. Later chambers leave room for several working machines, and the top score goes to the one built from the fewest pieces.
Keep notes
Write down what you think each dream does. Every player starts with the same meanings. Wake all 100 chambers and the dreams trade places: every symbol does something new, and you read them again from scratch.
Hints when you’re stuck
Hints are unlimited. One shows the shortest solution for a few seconds and costs that chamber 25 points.
Experiments and free play
Random experiments at five difficulty levels, with no score. Once the campaign is done, free play opens up: every dream, no walls.
Game Center and iCloud
Leaderboards and achievements through Game Center. Your progress follows you to your other devices through iCloud.
Four looks
Pick the look that suits your eyes, among them a colourblind theme with labels and a light theme.
$3.99, paid once. No ads, no in-app purchases, no account.
Sound
A machine that plays music
Turn the sound on and every dream has its own voice. As signals pass, the machine plays in the chamber’s key, and each chamber draws a new mood. A working machine is also a small piece of music.
For musicians: two AUv3 plugins
The app also adds two Audio Unit plugins for hosts such as AUM. One sends the board’s notes out as MIDI, the other plays the game’s own sound in time with your host. The game works fine without them.
The Sleeping Engine
Privacy policy
Last updated 12 October 2026
This policy covers The Sleeping Engine for iPhone, iPad and Mac, including its two Audio Unit plugins. The game is made and published by Tanel Teemusk. In short: the game collects no personal data.
What the game collects
Nothing. I don’t collect any personal data. The game has no analytics, no advertising, no tracking and no account to sign up for. Nothing about you or the way you play is sent to me or to anyone else.
Your progress and iCloud
Your progress is stored on your device. If you use iCloud, the game syncs that progress through your own iCloud account so it reaches your other devices. Apple handles the sync, and I can’t see or access that data. iCloud is controlled from your device’s settings.
Game Center
Leaderboards and achievements use Apple Game Center, and only if you sign in to it. Signing in is optional and the game works without it. Game Center is run by Apple, and Apple’s privacy policy applies to it.
Device permissions
The game does not use your camera, location, contacts or microphone.
Children
Since the game collects no personal data from anyone, it collects none from children either.
Changes to this policy
If this policy changes, the new version will be posted on this page with a new date at the top.
Contact
Questions about privacy go to Tanel Teemusk at hello@teemusk.com.
Support
Found a bug, stuck in a chamber, or have an idea for the game? Write to hello@teemusk.com or use the contact page.
The Sleeping Engine is made by Tanel Teemusk.