Guardians: Agents of Justice is a cancelled superhero squad tactics game developed by Simtex in 1996 / 1997, that would have been published by Microprose. The project was supposed to play like X-Com, but with superheroes. As we can read on Wikipedia, Simtex created a number of well-known turn-based strategy games for the PC, most notably the first two Master of Orion games, but the company closed in 1997 for economic problems. Guardians: Agents of Justice vanished forever with the closure of the studio.
Derboo was able to find a some screens of this game from a 1997 PC Champ issue and other korean magazines. RADIX also found some more screenshot in Computer Games Strategy Plus. If you have more images from Guardians: Agents of Justice, please let us know!