I remember playing Glider when I was a CCon (computer room consultant) back at Carnegie Mellon. It was usually on one of the macs if the lab had them. The game concept was very simple and kind of silly. You control a paper airplane as it glides through a house. You can move it back and forth some with the controls, but a lot of the game is using things in the environment to help keep you aloft while avoiding hazards. The company that published the game went bankrupt and the rights to the game reverted to the author, John Calhoun. He's now gone and made Glider available for free on his web site. It runs on OS X and Mac OS 9. It's always nice to see people keeping older games alive.