Mario Is Missing! is an educational game and the first game where Luigi is the main protagonist with Mario in a supporting role. The main gameplay consists of moving around a city in side-scrolling manner while jumping on Koopas to collect stolen artifacts.
This is one of those bad games where the concept is really good but the execution absolutely abysmal. Luigi and Yoshi traveling through time to save Mario is such a cool idea, maybe for a Mario and Luigi/Chrono Trigger type of game. Too bad it was used for this hellscape of game