In 1994, just a few months before changing their company name to 3D Realms, Apogee published a shoot-em-up for DOS developed by Cygnus Studios (now Mountain King Studios) and titled Raptor: Call of the Shadows. I downloaded the shareware version of the game from a local bulletin board system (BBS) and played it for hours on end.
I was impressed with the game’s cutting edge (for 1994) graphics, excellent sound effects, and fluid controls. I had played several shmups prior to trying Raptor, but the precision of the mouse-based control scheme was, in my eyes, far superior to controls for console-based shmups of the Super Nintendo/Genesis era.
I recently downloaded the shareware version again, loaded it using DOSBox, and recorded a video of my playing the first level with a trackball. Click past the break for the video.