The core has been ported from the MiSTer FPGA by obsidian-dot-dev. It covers Gauntlet, Gauntlet II and Vindicators Part II.
Designed by Ed Logg and originally released in 1985, Gauntlet was a coin-op smash for Atari. The sequel followed in 1986. The series also includes Gauntlet: The Third Encounter, Gauntlet III: The Final Quest, Gauntlet IV, Gauntlet Legends, Gauntlet Dark Legacy and Gauntlet: Seven Sorrows.
Vindicators Part II is the lesser-known sequel to the 1988 original. The first game was ported to the NES by Tengen.
You can grab the core here, or use an updater to add it to your Analogue Pocket.