Boxing is a Micro VS. Game & Watch game released in 1984 by Nintendo. In America, the game was originally known as Punch-Out!! (named after the popular franchise), though when the game was included in Game & Watch Gallery 4 they changed the name back to Boxing. The model number for the game was BX-301. Within the box of the game were the unit, LR44 batteries, and a caution leaflet. In the game, you'll box another character. The game is seen from a 2D perspective, and your character is always on the right.
The only difference between Boxing and Punch-Out!! were the names and the box. The American box had artwork that was made specifically for it.