1. Expose your plates
Begin an observation and expose the star field. You will work with a pair of plates, labelled A and B, so a small change has somewhere to reveal itself.
The game is an astronomy puzzle, not a scientific observing instrument. Its sky and measurements support the investigation inside GLASS SKY.
2. Develop at your own pace
Developing can include a forgiving timing exercise with three rounds. It is optional, so you can focus on comparing the plates when you prefer a quieter session.
Reduced flashing is enabled by default. Check the settings before you begin if you want to adjust the presentation.
3. Compare A and B
Use the comparison control with the mouse or press Space to switch between plates. Look for a point that moves, changes brightness or appears different from the surrounding stars.
Let the fixed stars anchor your attention. A convincing candidate should still make sense when you return to it more than once.
4. Mark a clue and look closer
Click either plate to mark the candidate you want to inspect. Use Z and X for the loupe controls and the arrow keys to move the close view.
Measure the candidate and compare its appearance across the pair. A bright point alone is a clue; its behavior helps you decide what to file.
5. Choose a classification
Classify the evidence as a comet, asteroid, variable, defect, known object or inconclusive. Not every interesting mark belongs in the discovery ledger.
Inconclusive is a useful result when the evidence does not support a confident answer. Careful observation matters as much as a striking find.
6. File and name your discoveries
File your observation to keep a local record. Eligible discoveries can receive a name between 2 and 40 characters, and the almanac lets you revisit your work.
Progress, a save backup and settings are stored on your computer. GLASS SKY has no account or cloud-save system.
7. Finish the campaign, then keep surveying
The campaign runs for twelve nights. Afterward, seeded endless survey keeps the observation loop open across six regions.
Vane's race appears on nights 4, 7 and 10 and draws on an earlier comet in the same region. Night 11 brings a bright-comet opportunity. Keep useful observations in mind as the campaign develops.
- Esc pauses the game.
- F11 toggles fullscreen.
- Use a mouse and keyboard; controller and Xbox support are not included.
- The game and official website are in English.