"Saucer" started when I wondered if I could make a video game that took advantage of the CoCo's unique joysticks, which return a 0-63 position for each axis. There were demos and art programs that recognized this, but most games just treated them like simple directional sticks. Could a satisfying game use the controllers to establish absolute screen positions, instead of direction of motion?
The first working version came together over a weekend, in seventh grade. I'm not sure how satisfying it really is (personally, I enjoyed playing it), but I think it is unique.
A little later, the opportunity came up for me to enter a program in a state math fair. So I retroactively made up a flowchart for Saucer (useless, but I suspect it made a difference in the contest), and I ended up winning third place. (I was vastly outclassed in resources by the first and second place winners, so I was pretty happy with third.)
Saucer needs a TRS-80 Color Computer with Extended BASIC, at least 16K of RAM, and two (!) joysticks. It probably can't be played in an emulator, because of the control system. (The screenshots here are mock-ups, accurate but enlarged.)
Your enemy is a flying saucer, similar to your own. It fires back only when fired upon, but it also moves, randomly, and you have to move out of the way. Six shots destroy the enemy; three shots, or one contact, destroy you. One joystick controls the position of your ship (for running away), and the other your crosshairs (for firing).
You either win the game, or lose -- there's no scoring, no multiple lives, and no endless parade of enemies or levels. Just a duel. (Note: There's no relation between this and the Atari game "Space Duel", which I learned of much later.)
The version here isn't the original. I had a variety of undated versions (no dates on the CoCo!) across multiple cassette tapes. Around 1997 (when Saucer was already about 15 years old), I put together the best bits and cleaned it up a little. (It could still use a little more cleaning.) But it looks and plays the same.
I also wrote a separate intro program for the fair. This one I haven't cleaned up. The bit about the protective "field" that the enemy sometimes entered was just cover for a bug (fixed in this version). :)
Download Intro (ASCII)
Download Saucer (ASCII)