Fueled by the previous year's release of the colorful and appealing Pac-Man, the audience for arcade games in 1981 became much wider. Pac-Man influenced maze games began appearing in arcades and on home systems. Pac-Man was again the year's highest-grossing video game for the second year in a row. Nintendo released the arcade game Donkey Kong, which defined the platformer genre. Other arcade hits released in 1981 include Defender, Scramble, Frogger, and Galaga. The year's best-selling home system was Nintendo's Game & Watch, for the second year in a row.