DOS Games made for DOS require an emulator to run on Windows. Use DOSBox or a frontend like D-Fend Reloaded and read this guide to play DOS games on your Windows PC.
There are two versions of the game, the shareware version, and the commercial version. The shareware version allows the user to play planets one and two, while the commercial version grants access to all six planets. Ste Cork declared the registered version freeware on July 23, 2008.
The above text is licensed under the GNU Free Documentation License. This text is based on this Wikipedia article.
Search on eBay