Lunar Lander
You are in command of a lunar landing module trying to make a safe landing on the moon, but boy are some of those landing pads in strange places.
Once of my earliest games, written as I was both fascinated by the arcade version of the game, one of the 1st real arcade machines I ever played, and also due to the application of gravity and momentum in a game. I even made a version of Lunar Lander for a Casio Calculator at an early stage, completely text based that got you to allocate the amount of fuel to burn as you descended.
This version has one landing pad per stage, with quite a few stages, all stored as a sequence of line points, including the position of the landing pad. Once you reach the end of all the stages, you go around again, but with higher gravity.
You can see a video on the game here.