MellowHigh was met with generally positive reviews from music critics. Lizzie Plaugic of CMJ stated, "The trio proves it has a fat bag of tricks: floaty fast rhymes (Get’n Drunk), high gravity boom bap (Troublesome) and haunting alien lullabies (Nobody)." Kyle Kramer of Pitchfork Media said, "These beats are huge, intimidating walls of sound. It may be that surprising people is a young man's game, and it's time for Domo Genesis and Hodgy Beats to settle into their comfortable roles as confident, reliable spitters. But for an album that sounds as off-the-wall as MellowHigh, it feels like a bit of a cop out to be content with insubstantial rapping." Laurence Day of The Line of Best Fit said, "The overall result is something that painfully needed some outside influences, perhaps another producer to steer them in a worthwhile direction – it’s an aimless, winding record that occasionally stumbles upon greatness."
