File:Singularity.png

Screenshot of Endgame: Singularity version 1.00.

  The image of the earth is NASA's "The Blue Marble: Land Surface, Ocean Color
  and Sea Ice".
  http://visibleearth.nasa.gov/view_rec.php?vev1id=11612
  
  NASA Terms of Use
  
  For all non-private uses, NASA's Terms Of Use are as follows:
  
  1. The imagery is free of licensing fees
  2. NASA requires that they be provided a credit as the owners of the imagery
  
  Visible Earth Addendum
  
  Beyond the NASA Terms, the Visible Earth team requests, but does not require:
  
  1. The Visible Earth be provided a credit as the location that the imagery was found at
  2. A URL be provided, either to the Visible Earth
     (http://visibleearth.nasa.gov/) or to the page providing the link to the used image.

  The boxy font used is "Acknowledge", by Brian Kent, modified in order to have the
  numbers fixed-width.
  http://www.aenigmafonts.com/fonts/fontsa.html
  
  Terms of use (quoted from an eMail from Brian Kent):
  
  ===
  Hi,
  
    Feel free to use the font any way you want to.
  
  --
  From
  Brian Kent
  aefonts@frontiernet.net
  ÆNIGMA GAMES & FONTS
  http://www.aenigmafonts.com/
  ===
  
  Note that this is /not/ the license available on his website; Brian has given
  us directly 'free to use for any purpose' licensing on this font file.  Thanks
  so much, Brian!

All the above information is from the games readme.

Everything seems to fit CC-BY-SA 3.0.