Unless you owned a pre-OSX Mac in the 90s, you probably never heard of it. Even if you did have one, you may have been too busy playing whatever arcade classic Ambrosia software had ripped off and charged $25 for. If you were lucky, you played some Exile or Realmz too.
Glider PRO was the third in a series of "Glider" games in which the player must guide their paper airplane, room-by-room, through an obstacle course comprised of common household objects. The glider cannot gain lift on it's own, and must use floor vents or candles to gain altitude (being careful not to set yourself on fire with the latter). Solid objects like tables, dressers and cabinets kill you, as will landing on the floor.
The paper theme was carried consistently throughout; extra sheets of paper were extra lives, rubber bands could be shot to defeat enemies, knock over grease jars or hit distant switches. Tin Foil became armor. Batteries could be used for a speed boost. Clocks (which used the system clock to maintain accuracy, calendars did this as well) gave you extra points.
Enemies included paper helicopters, Dart gliders and balloons. There were also paper shredders, toasters, fishbowls with hungry fish, basket balls and quite a few others.
What makes GliderPRO stand out, and what has allowed it to maintain a cult-like following that continues to this day, is the powerful "House Editor" that was included with the game. Players could create their own obstacle courses, choosing the room type, layout of furniture, and puzzles. They could also add custom room art or objects, which allowed some intrepid players to completely change the setting (one house, for example, was a castle made entirely of custom art). The amount of time I spent designing my own house and having people play it well outpaced the amount of time I actually spent playing the actual game. This, more than any other experience in my youth, is what made me want to get into game development.
Glider also had a lot of charm; it has serious Art Deco styling, a sort of Middle American identity. It had some catchy music to boot.
Something about the cleverness of flying a paper airplane, combined with all of the design choices that fed into that decision (office supplies as power ups, household goods as hazards, etc) just made it stand out, and it remains unique amongst games even today.
It also helped that this and Marathon never ever ever ported over to PC when they were relevant: this is one of the few gems that Mac owners could call their own.
Here's a crappy quality video, but you can see the basic gameplay, hear the music, etc;
http://www.youtube.com/watch?v=ndrlCbR-ZSo&feature=player_embedded
Alright, where are my old school Mac Gamers (lol) at?