This game is very interesting, because, at least in my experience of Basic text adventures, this is the only multi-player game I have ever come across. Each player gets a number of turns to explore the world of the game, which is quite extensive. You can either be a baddie alien, in which case you go around trying to kill the humans you come across. Or you're a human character, in which case you have to collect various items and interpret various clues, in order to figure out how to thwart the alien invaders. The game allows you to play alone, but the story and puzzles are fairly simple (I've only played through as a human). I image the time pressure created by trying to complete your appointed tasks before the other player completes theirs (or "players"--it allows up to 5 to play), must add a nice element to the challenge. I can't imagine the game is much fun to play as just the alien character alone, as it would simply be an exercise in moving until you have run across all the human players and killed them. The combat seems somewhat random, although there are weapons that can be picked up at various locations in the game. I'm unsure if they affect combat. There might be opportunities as an alien character to interfere by seizing or moving objects with the other player's ability to complete the game. However, combat can make the players drop things, if you are willing to risk possible death, so there are ways for human characters to win objects back. I am unsure if, when played with others, it is recommended that they not be allowed to view the screen, but I suspect that this might be so (or an "option"). In that way, if you're an alien you can hide or move objects, and the other player will have a harder time finding them or knowing when they need to confront you to try to force you to drop them. If you're a human character, it would give you the opportunity to try to hide or use circuitous routes to get to objects unmolested. I suspect knowing the original book series would also add to game play (although I think names have been changed to protect the original author against a copyright challenge--for example the series is called "The White Mountains" series, not "High Mountains"). I played a version of the program ported to the TRS-80 MC-10 from a version for the VZ200. In the course of porting the program I slightly condensed some of the descriptions and fixed some grammar and spelling errors.