At Metacritic, which assigns a weighted average score out of 100 to reviews from mainstream critics, G Is for Deep received an average score of 66% based on 7 reviews, indicating "generally favorable reviews".
Zach Long of Alarm said, "[Doseone] puts the entirety of his vocal range on display throughout G is for Deep, layering voices on top of one another to create a veritable choir." Bram E. Gieben of The Skinny gave the album 4 stars out of 5, saying, "the beats, which Dose produced, are heavily electro-influenced, with a melodic pop sheen that suits his approach to vocals on this release." Daniel Sylvester of Exclaim! felt that "G is for Deep remains an album driven by lustrous compositions and like any good artist, Doseone's voice dutifully abides."