Image credits
The landmarks drifting past in the background are real photographs.
First image of a black hole (M87*, 2019)Event Horizon Telescope Collaboration / ESO — CC BY 4.0
Crab NebulaNASA, ESA, J. Hester and A. Loll (Arizona State University)
Pillars of Creation, Eagle NebulaNASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Pluto, in true colorNASA / Johns Hopkins APL / Southwest Research Institute / Alex Parker
Mercury, in true colorNASA / Johns Hopkins APL / Arizona State University / Carnegie Institution of Washington
Everything else in the sky is drawn with CSS. Sound effects are credited in the game folders.