The Zork games descend from the very oldest computer games. The original Zork was released in 1977 on the PDP-10, a mainframe computer and was influenced by an even older game, Colossal Cave. The first several Zork games were ultimately released on a very wide range of computer systems. These games didn't have simplistic graphics, they had no graphics at all. The Zork games were considered "interactive fiction" and they were played by typing in various commands (e.g. "hit the troll with the Elvish sword").
Many Zork games, spin-offs and other games using the same engine were released by Infocom throughout the years before Return to Zork was released after a five year hiatus for the series. While the original Zork games were text based, Return to Zork was a graphic adventure, somewhat similar to Myst which was released slightly later. While there have been a few Zork games released since, Return to Zork was the last to be published under the Infocom label.
The Zork games all exist in the same universe and there is a cohesive timeline that the games are all a part of. Return to Zork is set later than any other Zork game. It is set so far into the future that the events of past (and future) Zork games are practically mythology. The plot of Return to Zork is not terribly original though. Some dark force has gripped the land. Evil creatures infest the area, things have unnaturally decayed and even entire buildings have disappeared. Your job, of course, is to find out what is causing this and to stop it.
Return to Zork received mostly positive reviews. There are purists who will hate the idea of the transition from all text to a graphical adventure but taken on its own it wasn't a bad game. Bugs did hamper the game by making it a little harder than it needed to be. Still, it wasn't a huge issue. Those that like the original Zork games or graphic adventures in general should definitely give this one a try. You don't necessarily have to track down an original copy as Return to Zork has been updated and released via Steam and GoG (where it can be had for a mere $1.97 currently) - https://www.gog.com/game/return_to_zork.
Screen shots above are from the DOS version of the game.