Catch the light.
Before it’s gone.

THE OBSERVER’S FIELD GUIDE

A fleeting kind of treasure.

Cosmic bursts are fading. Your telescope starts at the crosshair. Select a numbered burst on the map or in the signal list, choose an exposure, then observe.

1. Move with purpose. Travel takes 1 second plus the sky distance divided by 12, rounded up. A nearby route saves light.
2. Balance your exposure. A longer exposure collects more light, but every burst dims as mission time passes. Finish by its fade time and the night’s time limit.
3. Make the night count. Reach the light goal for a silver seal; reach the gold line for a gold seal. Each burst can be observed once.

The clock advances only on an observation. Plan as long as you like. Undo, restart, and route hints are free. A hint uses the exact best remaining route; you can still choose your own.

These are fictional integer-time puzzles, not scientific observations. Light = brightness × √(exposure / 6) × remaining brightness at mid-exposure, rounded to the nearest whole point.

THE SIGNAL GOES ON

For the light chasers.

Inspired by the closing chapter of NASA’s Swift mission in 2026, and the astronomers who race to follow fleeting cosmic outbursts. Lastlight is an original, fictional strategy game. It does not reproduce Swift flight operations or real target data.

Observation-planning research reference: astropy/astroplan (BSD-3-Clause). No upstream code or artwork is incorporated. Original game code: MIT. Nebula illustrations: generated with a GPT image model, optimized and bundled locally.

Read NASA’s Swift mission farewell · Source & art notes · License

Your night seals are saved only on this device. No account is needed. Sound is synthesized locally and starts off.