(There's no video for Galaxy yet. Please contribute to MR and add a video now!)
Galaxy is probably the smallest (1.7KB !!) program for Mac from 1985. All it does is display moving white dots almost identical to the 1992 Windows 3.1 screensaver called "Starfield". There is absolutely nothing else to it, no about window (we do not even know who the author is) and pressing the mouse button quits. That's it.
Galaxy.sit (1.28 KiB / 1.31 KB)
Galaxy / compressed w/ Stuffit
Mac OS 1.x - Mac OS 9.2.2
Emulating this? It should run fine under: Mini vMac