He had tried the newer versions. They were beautiful, pristine, polished to a mirror sheen. But they felt manufactured. In 0.9.8.0, the universe felt ancient and indifferent.
The silence in his headphones was absolute. Then, the low, resonant drone of the simulation booting up filled his ears. It wasn't a sound effect; it was the audio rendering of cosmic background radiation, turned into a mournful hum.
Because this is an older build, it is less demanding than the modern version, but still requires a decent GPU: Windows 7, 8, or 10. 4 GB minimum (8 GB recommended).
: It is the final comprehensive version released for free on the official website before the 0.9.9.0 Steam debut.
Vladimir Romanyuk (the developer) explicitly released all versions prior to 0.990 as freeware under a non-commercial license. You are free to download, share, and use them, provided you do not sell them or claim them as your own.
The software is less of a "game" and more of a digital planetarium. It uses procedural generation based on real astronomical data to fill in the gaps of the unknown universe.