You are able to use your coins given to you in the Subspace Emissary and use them to shoot at the Trophies and Stickers in the minigame. Some trophies are required to be hit by the coins multiple times. And some bombs in the minigame will try to hit you, lowering the amount of coins you have. But, if you hit the trophies and stickers enough times you may be also to get some extra coins.
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