music/galaxy.opus - Mid-Air Machine - Creative Commons Attribution-ShareAlike
music/wormhole.opus - Page Asgardius and Mid-Air Machine - Creative Commons Attribution-ShareAlike
backgrounds/galaxy.png - NASA - Public Domain
backgrounds/wormhole.png - Pixabay - Public Domain
backgrounds/crash.png - Pixabay and Page Asgardius - Pixabay License
backgrounds/antenna.png - NASA and Page Asgardius - Public Domain
backgrounds/supernova.png - NASA/JPL-Caltech - Public Domain
sprites/ss.png - Pixabay - Pixabay License
sprites/css.png - Pixabay - Pixabay License
sprites/sat.png - NASA - Public Domain
sprites/asteroid.png - NASA - Public Domain
sprites/radio.png - NASA and Page Asgardius - Public Domain
sprites/iss.png - ESA/NASA - Creative Commons Attribution-ShareAlike 3.0 IGO
sprites/wallh.png - Page Asgardius - Public Domain
sprites/wallv.png - Page Asgardius - Public Domain