Mario is Missing!
The gameplay consists of moving around a city in side-scrolling manner while jumping on Koopas to collect stolen artifacts (pieces of famous landmarks). Luigi then must take these artifacts to their respective locations and correctly answer three questions about the landmark. During the quest to return all three artifacts to their proper landmarks, Luigi must determine his location in order to receive the assistance of Yoshi . If Luigi takes Yoshi to the correct location, he can ride him for double the walking and running speed. He can then proceed to another town to do it all over again.
In the introductory sequence of the NES version, Mario is captured by an unidentified green Koopa -like creature, which is thought to be a poor depiction of Bowser.
The PC / Super NES version has more plot: Bowser has set up a castle in Antarctica , and plans to use many hair driers from the Hafta Havit mail-order company to melt the Antarctic ice and flood the Earth. He sends his Koopas to different cities across the Earth to steal artifacts in order to fund his operation. Mario, Luigi and Yoshi journey to Bowser's castle in an attempt to stop him. Luigi is hesitant to go in, so Mario goes by himself and is captured by Bowser (though in the SNES version, Mario doesn't even take a step toward the castle before a trap door opens beneath him). Luigi must now rescue Mario by completing levels in Bowser's castle; each floor is guarded by one Koopaling and contains a number of pipes which transport Luigi to a city containing Koopas. The SNES version contains three Koopalings (Ludwig, Roy, and Iggy), while the PC version has all of them actively guarding Mario except for two; Lemmy was absent because he wanted to play in the snow, and Morton simply didn't want to get involved. Princess Daisy makes a cameo in this game. She is the person at the information booth.
Once there, Luigi is able to question the locals to gain clues as to his current location, the general direction of remaining Koopas, and information about the affected landmarks. He is given a map and a cellphone , with which he can make and receive phone calls. Throughout the game he receives several phone calls from Mario, which become increasingly urgent. Powerups such as 'Koopa finders' and 'taxi tokens' can be picked up in each city. Once an artifact is returned, the landmark is reopened, and Luigi can then enter this landmark to view it and to take a snapshot which can be viewed later. Once Yoshi is sent to the correct location and the exit pipe is found, Luigi is returned to the castle where he will proceed to the next pipe. Once a floor is completed, Luigi must defeat the Koopaling guarding that floor to proceed to the next. Each city has a certain style of music playing in the background, for example, New York has muzak playing
The NES version, unfortunately, lacks image quality. The gameplay is totally different from the SNES version, while still having the same basic story. Rumor is that Nintendo regretted bringing this version out after the SNES and DOS versions, because it made them look bad.