Your mission is to explore Purgatory and its surrounding desert, find whatever has left the town deserted, and destroy it before it wreaks havoc on anything else. You could become a hero or a small pile of ashes. What happens is up to your skill in logic and your ability to make use of any equipment you might find.
Sean Murphy maintains a webpage about this game.
[+] Users who have solved this game
[+] Users currently playing this game
This constitutes an interesting game with many red herrings and blind alleys. It feels like two games stapled together; the first being Old West and the second Science Fiction. The desert area is quite tough to map.