Rieselzeit app icon: an hourglass with a brass frame on a warm background.
Android · Logic puzzles

Measure time in sand.

Measure exactly nine minutes with a 4-minute and a 7-minute hourglass. Rieselzeit turns the classic brain teaser into a calm puzzle game: turn glasses, let the sand run, ring the bell at the right moment.

Play in the browser View screenshots
Coming soon to Google Play
Rieselzeit on a phone: puzzle 2-5, the bell is to ring after exactly 9 minutes, below it two hourglasses of 4 and 7 minutes.

The game in the browser

The same version as in the app, with no account and no installation.

Controls

  • On a phone: tap an hourglass.
  • With a keyboard: keys 1 to 4 turn a glass, space lets time run, G rings, Z undoes, H shows a hint.

Notes

  • Storage: Progress and settings stay in this browser.
  • Language: follows the device, can be changed in the settings.
  • Offline: works without internet after the first load.
In its own window

Screenshots

Taken from version 1.0.

An hourglass has run out and time stands still. The left glass is being turned over.
Time stands still: when a glass runs out, everything stops. Now glasses may be turned, even a half-run one.
Puzzle solved: three stars, spot on, 4 moves with a best of 4.
Spot on: the fewest moves earn three stars.
Daily puzzle number 4: two hourglasses of 9 and 10 minutes, linked by a lever.
Daily puzzle: a new puzzle for everyone every day. Each weekday has its own twist.
Start screen with a large hourglass, below it Play and the daily puzzle.
Workbench: warm light, brass and glass, sand falling grain by grain.

Rules

Scope and privacy

Permissions: vibration while playing. The app does not ask for location, camera, microphone or contacts.

Technology

A web game with no engine and no third-party libraries. It runs in the browser, as a web app and as an Android app.

How it is built

A generator builds the puzzles, a solver finds the shortest solution for each. A check replays every solution through the same functions as the interface.

Hourglasses, sand and light are drawn live, every grain falls on its own. Sounds are generated in the browser, with no audio files.

Contact

The form below is available for questions about how it is built, the decisions behind it, or how it might carry over to another case.

Arithmetic check Arithmetic task, shown as an image

Your details are processed in order to answer your enquiry. More in the privacy policy.

No Google captcha, no cookies, no disclosure to third parties. Alternatively by e-mail to info@timobritz.de.