A shoot'em up text adventure written by C.E.J. Pacian using the TADS 3 Interactive Fiction programming language.
The in-game description says:
"Mute Lawton: gunslinger, former lawman, bit on the quiet side. The man he loves is to be hanged at noon, separated from him by a nuclear wasteland and an indifferent civilisation in its twilight years. The sheriff's posse awaits: corrupt and power-hungry, possessing strange and lethal skills, augmented by archaic technology. You can't talk your way out of this, can't save a man's life by picking up random objects or looking behind desks.
You'll have to draw fast and aim true."
The game can be downloaded from the interactive fiction database: http://ifdb.tads.org/viewgame?id=xwedbibfksczn7eq