Maggie Lee of The Hollywood Reporter wrote that while the film contains a high level of stylised violence, "it is not an artistic exercise.

The King of Pigs captures many subtle class gradations in Korean society and shows how it corrupts human interaction."

Lee also wrote: "Technically adept and highly cinematic in its storytelling, the US$150,000 production proves that it is still possible to produce quality animation with a modest budget.

"[7] Peter Bradshaw of The Guardian awarded the film four stars out of five, and called it "a strangely gripping and upsetting movie.

[9] Korean cinema website KoreanScreen gave the movie a 4 out of 5 stars, writing, "Bleak, angry and utterly uncompromising, this animated view of hierarchical high schools delivers a relentless break-time punch to the stomach.

"[11] A web series adaptation of the same title, produced by Studio Dragon and Hidden Sequence, premiered on the online streaming service TVING on March 18, 2022.