Upon release, the album received critical acclaim, with particular praise for the lyrics, dark sound,[7] and Smith's vocals.

[10] It also reached number one in Austria, Belgium, Denmark, France, Germany, Greece, the Netherlands, Poland, Sweden and Switzerland.

Five of the album's songs, including "Alone",[11] had been performed live in 2022 and 2023 during their Shows of a Lost World worldwide tour.

[4]: 109  AllMusic described the song as "dense swirls of synths, simple, pounding drums", noting that "themes of loss, isolation, impermanence, and mortality" were present in the lyrics.

[12] "I Can Never Say Goodbye" was written after Smith's brother's death; he said he "didn't want the words to dominate the song, in a way that the music can become a backdrop to what you're singing.

"[14] "Endsong" was inspired by a starlit night that reminded Smith of when he watched Apollo 11 land on the moon in 1969 with his father in their backyard.

[15] In several interviews following the release, Robert Smith noted that the album was originally intended to be much darker, with his wife Mary Poole ultimately stating that "people won't listen to this", resulting in several track changes and revisions, such as the inclusion of "Warsong" and "Drone:Nodrone", both of which were not on the original running order.

[17] On 14 October 2024, Smith said that a tour in support of Songs of a Lost World will begin in "autumn next year" after the completion of a projected follow-up album.

[28] Franck Vergeade of Les Inrockuptibles reported that "only two listens were authorized by the record company" to review the album: he qualified it "flamboyant gothic".

[33] Éamon de Paor of The Irish Times praised the album, giving it four stars and describing it as "majestically desolate, gorgeously grim", adding that it "moves like a glacier at midnight – magnificent, unstoppable and with a chill that settles in hard and heavy and does not leave".

De Paor likened the sound of the album to bands such as Nine Inch Nails, Cocteau Twins, Pink Floyd, and New Order.

"[7] Victoria Segal of Mojo gave the album four out of five stars, praising Smith's vocals: "On a record so alert to the cataclysmic effects of mortality, it's remarkable how fundamentally unchanged Smith's voice is", while also noting the album lacked anything "approaching a pop song ...

"[8] The Times's Will Hodgkinson praised it in a five-star review saying: "On the goth rockers' first album in 16 years, Robert Smith tackles the death of loved ones and his own demise in music of expansive sophistication.

[39] However, the German edition of Rolling Stone was less enthusiastic and criticized the album for "flat songs" that sounded "redundant" with endless introductions.