HÜNFELD, Germany—Looping Louie was named Germany’s children’s game of the year in 1994. It took two more decades for the contraption to earn its current superlative: One of this country’s most popular drinking games.

Designed for preschoolers, Looping Louie is a four-player tabletop game with a motorized plane that circles around the board, knocking off players’ tokens. The story line is that Louie, an aviator with a deranged grin and thick mustache, is swooping down to players’ barns to scare away their chickens. Players press levers that launch Louie over their barns and toward other players.

German millennials, many of whom played Looping Louie as children, have added another rule: a shot of Schnapps or swig of pilsner after every loss. “Normally it’s for small kids,” said Rebekka Hofmann, a 21-year-old dressmaker from Burghaun, Germany. “But with drinking, we turn into small kids.”

Looping Louie has become a cult phenomenon in Germany, inspiring Internet memes, making a cameo in a German music video and becoming a mainstay in university dorms and shared apartments nationwide. Rhode Island-based Hasbro Inc. discontinued the game years ago in the U.S., but following Louie’s takeoff in Germany, the company is now planning his return.

In Germany, a country with 81 million people, Looping Louie has sold more than 1.3 million copies since 2006—far more than in any other country, according to Longshore Ltd., the game’s Hong Kong maker. A game with a quarter of those results would be considered a success, Longshore said. Hasbro, which distributes the game in Germany, said Looping Louie has “a cult following” but declined to discuss sales.