This is the first in the long, varied series of Chunsoft’s Mysterious Dungeon (or if you’re a prude, Fushigi no Dungeon) series. All of the games in the series have one thing in common: lots and lots of dungeon crawling. I’ve never actually played Rogue, keep in mind, but it’s hard to imagine this being anything different. You run around in a series of randomly generated dungeons, consisting of lots of rooms connected by small corridors. Randomly generated dungeons at their finest, here! And you fight monsters, and collect all manner of randomly generated treasure, and do it lots and lots of times.
This game involves Taloon (or Torneko, if you played its Playstation sequel, Torneko: The Last Hope (or the nonexistent English-language Dragon Warrior IV for Playstation)) leaving his home of Endor in search of fantastic treasures and whatnot. He eventually reaches the Mysterious Dungeon, and decides to poke around for a bit. And there you have it.