The album sound draws mostly from pop and retro production, with its songs incorporating eclectic styles ranging from disco and pop-rock to Miami bass and balearic beats.

The album was met with generally favorable reviews from critics, who praised the sophisticated retro, pop production and the EP's mature themes.

It features genres such as disco, pop-rock, blues, Miami bass, R&B, and dance-pop, with heavy influences from house, dream-pop, latin, and balearic beats.

A variety of songwriters and producers also participated, including Melanie Fontana, LDN Noise, Tayla Parx, Lindgren, Lostboy, Earattack, and Lee Woo-min "Collapsedone".

[10][11] The lyrics revolve around the protagonists finding the courage to confess their love to a crush, with lines such as "I've been hiding how I feel for you forever" and "Now that it's off my chest there's room for you and me".

[21][22] On the album's release date, the Empire State Building was lit up in Twice's official colors in collaboration with non-profit organization Musicians On Call, celebrating the "healing power of music".

[23] Rolling Stone's Tim Chan gave the album a positive review, stating that Twice "blows up the tired stereotypes and smashes through barriers with a seven-song set that’s as brash and compelling as anything in the pop music landscape today".

[12] Rhian Daly of NME gave the album a rating of four out of five stars, noting that it further refines Twice's sophisticated and retro-inspired sound, despite some "awkward junctures".

[7] Lai Frances, writing for Uproxx, praised the group's "newfound image of bringing sophisticated pop with mature themes.

"[8] AllMusic's Neil Z. Yeung concluded his review by saying Ready to Be keeps "the energy and euphoria at a peak" and "is another serving of addictive pop moments from the confident and stylish nine-piece".

[24] Han Seong-hyun from IZM wrote that "while the impressions left by 'Set Me Free' and 'Moonlight Sunrise' are somewhat flat, the rest of the tracks that follow succeed in immediately engaging and immersing the ear".

[27] Paste ranked it the 8th best K-pop album of the year, who called it "more sophisticated and mature than ever before with assertive claims of control and defiance made throughout the lyrics".