Upon its release, "Power Up" received positive reviews from critics for its catchy and addictive nature, further commenting the song as a "perfect" delivery for the summer.

The group shared during a press conference for their second solo concert "REDMARE" in Seoul that they felt burdened by the success of their first summer single but were confident that the new track would be "another summery earworm".

Member Wendy compared "Power Up" to "Red Flavor" and said that if the latter "reminded people of fresh fruits" then the former would "give energy, like its title".

[3] Similarly, the group's leader Irene thought that in comparison to "Red Flavor", the song "takes a little more time to stick", initially not liking it immediately herself.

Seulgi mentioned that the "encouraging message" came from SM Entertainment's executive producer and founder Lee Soo-man, who often told the group at a company workshop "You have to enjoy yourself whether you are playing or working" which they included in the song's lyrics.

Tamar Herman of Billboard called the repetition of "banana-na-na" throughout the chorus "Minion-esque" and said they created a tune "built to reflect the lazy days of the season".

[10] Red Velvet performed the single along with other tracks from Summer Magic before its official release during their second concert 'REDMARE' on August 5, 2018, revealing them to the public for the first time.

[11] An accompanying music video directed by Kim Ja-kyoung of Flexible Pictures and choreographed by Kyle Hanagami was released in conjunction with the single.

Hong Dam-young of The Korea Herald compared it to "Red Flavor", saying it wasn't as catchy and commented that "One might need to push the replay button twice or three times in order to fully vibe with 'Power Up'.

[20] "Power Up" topped all of South Korea's music charts upon its release, allowing the group to achieve a "Perfect All-Kill" for the first time in their career.