Donkey Kong (US set 1) with Hard kit is a US arcade release of Donkey Kong that includes an additional 'Hard kit.' This kit likely modified the game to increase the difficulty, possibly through changes to enemy behavior, level design, or scoring systems. The addition of the hard kit was not a standard feature and indicates a way for players to extend the game's challenge. Nintendo developed and released the game.

Donkey Kong (US set 1) with Hard kit

Donkey Kong (Japan set 1)