A special item which, when obtained, provides the player with some asset that is necessary for or makes easier the process of beating the game.(noun)
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Use "power-up" in a sentence
"You best judge your jumps correctly or whether or not you should use a star power-up to zoom ahead or if you think you can totally outswim those jellyfish (you can't)."
"Dokki Doki and Shugo Chara Pucchi Puchi! will follow the current anime series as its power-up."
"In order to power-up these criminals for use in “mechanical warfare and mayhem”, they go through orientation after the weaker criminals are violently weeded out."