20,000 Light Years Into Space is free software, licensed under the GPL. If you don't have a Windows computer, you can play the Source code version by installing Python 2.4 and Pygame 1.7 (or later versions).
1.4 is a minor update to the game that introduces various bug fixes, released ahead of a planned major update which is currently in development:
1.3a Replaced some sound effects with new versions.
1.3 Repackaging for Linux distributions.
1.2a Source release only: Bugfix for 'SDL_ttf render failed'. There is no need to upgrade if 20K Light Years works on your machine. Also, the game now stores savegames and configuration data in your home directory (if you have one), and you don't need to run the game from the game directory.
1.2 Pygame.org release. Includes various presentation tweaks.
1.1a Source release only: Pygame version detection bug fix. No change to save file format or game rules.
1.1 Includes many minor improvements, and one major change that directly indicates flow.
1.0 (RC2) Version handed in to Pyweek.