Communion debuted at number one in the United Kingdom and spawned six singles: "Real", "Take Shelter", "Desire", "King", "Shine" and "Eyes Shut".

Alexander said that some of the lyrics in "Real" were inspired by experiences he had with a former boyfriend: "When I met him, I was really wasted and I fell off a bin and had to go A&E because I sprained my wrist, so I put in the line, 'Broke my bones playing games with you'.

[12] In an enthusiastic review, AllMusic rated the album 4 out of 5 stars, highlighting the group's ability to skillfully bridge the "ambient '80s style synth-pop of M83 with the funky dancefloor grooves of Justin Timberlake" and transform their influences into something new.

[13] In another 4 out of 5 review, DIY praised singer Olly Alexander for managing to avoid cliché while tackling well-tread subjects such as heartbreak and loneliness, and remarks that the group adds a human touch to powerful pop anthems.

[16] Alexis Petridis of The Guardian wrote that the group doesn't "seem to have an original idea in their collective heads", but still acknowledged that the album's "watertight" pop songwriting made it enjoyable.

[15] Jon Caramanica of The New York Times made a similar critique of the album, to which he referred as "diet-club music", but again praised the songwriting as excellent and effective.

[21] In an overall positive review, Billboard noted that the group has a "skill set, not a sound", particularly pointing out the album's strong melodies, emotional honesty and broad tastes.