1-Up Heart

From the Super Mario Wiki

1-Up Hearts basically perform the same function as 1-Up Mushrooms, that is, awarding one Extra Life to the player in Super Mario Land. However, unlike most Mushrooms, 1-Up Hearts will remain in one place until Mario grabs it, whereas the 1-Up Mushroom would slide away from Mario unless he could quickly catch it. However, in Super Mario Land 2: Six Golden Coins, the 1-Up Heart moves like the 1-Up Mushroom. In fourth stage of Macro Zone, the 1-Up Hearts could be caught by Pumpkin Zone's witch boss, who ran away from Mario with them. These 1-Up Hearts also appeared in mini-games in both games.

Most likely, the reason 1-Up Hearts were used in these games rather than 1-Up Mushrooms was that the black-and-white palette of the original Game Boy would make it impossible to distinguish between 1-Up Mushrooms and Super Mushrooms.

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