1 UP Heart

1 UP Hearts (alternatively 1UP hearts, 1-Up Hearts, or simply Hearts ) basically perform the same function as 1-Up Mushrooms, granting one extra life to the player in Super Mario Land, Super Mario Land 2: 6 Golden Coins, Donkey Kong on the Game Boy, and the Game & Watch Gallery series. The most likely reason that 1 UP Hearts are used in these games rather than 1-Up Mushrooms is that the monochrome palette of the original Game Boy would make it impossible to distinguish between 1-Up Mushrooms and Super Mushrooms.

Super Mario Land
1 UP Hearts make their first appearance in Super Mario Land, when a 1 UP Heart is released from jumping under a Mystery Block or Brick Block, it will pop out by falling straight down and remain in one place, unlike the Super Mushrooms, they will fall through the ground until Mario grabs it in time before disappearing.

Super Mario Land 2: 6 Golden Coins
In Super Mario Land 2: 6 Golden Coins, the 1-UP Heart moves like the Super Mushrooms, unless it touches a wall that will make it go the other way and vice versa until Mario catches it. The 1-Up Hearts can also be caught by a Keipu, who then runs away with them. In bonus games that occur if Mario rings the bell placed hanging in the air at the end of a stage, 1-Up Hearts become available prizes; in the Crane Game and Ladder Game, 3UP Hearts exclusively appear in the Crane Game and give three extra lives. Stand-alone 1 UP Hearts can be found in some levels.

Donkey Kong
In Donkey Kong on the Game Boy, 1 UP Hearts float in midair at spots that are hard to reach without special moves. They reappear if the player loses a life and revisits the level. They appear slightly larger and has the "1 UP" logo on them.

Game & Watch Gallery series
1 UP Hearts appear in "Modern" versions of Game & Watch games in Game & Watch Gallery and its sequels. These hearts replenish a life that was lost and only appear when a player reaches 200, 500, and 700 points in most games; if a player does not have any misses when they pass these points, a heart does not appear. In this game, they are either, red, pink and have a two-toned color scheme similar to the one suggested by the white and gray pattern of the original hearts in Super Mario Land. Despite being monochrome friendly items, 1 UP Hearts still appear in Game & Watch Gallery 2 for the Game Boy Color (excluding Japan which released for the original Game Boy) and its sequels for unknown reasons.