"Sun of a Gun" received positive reviews from critics, who praised its "ready for the dancefloor" theme, in addition to it being a "standout track".

[4] It was written by Jimmy Harry and Nanna Øland Fabricius, while Dave McCracken served as the song's executive producer.

[6] In an interview with MTV News, Oh Land described it as a "love story" about "a person who's kind of destructive, but you keep coming back because you can't let it go".

[4] Andrew Leahey from AllMusic commented that the "four-on-the-floor breakup anthem featur[es] snaps, synthesizers, and background vocals that sound like pan pipes".

[2] Sal Cinquemani of Slant Magazine claimed it "juxtaposes a driving 4/4 beat with accompanying madrigal-style vocal harmonies".

[8] while Fraser McAlpine of BBC opined that it "appropriates some of the primal chanting and hollering of Tune-Yards, but brings in a big pop chorus".

[10] A critic from Sunset in the Rearview called the single a "pop winner",[11] while DeShaun Zollicoffer of GeekRevolt labelled it a "stand out track".

[12] Additionally, a reviewer from Mixtape Muse found "Sun of a Gun" and album track "Voodoo" good for dancing.

The single first entered the United States Dance Club Songs chart, peaking at number 12 for the week ending April 9, 2011.

As the track's chorus begins, the light side of Oh Land appears, in a skin-colored dress and longer hair, in front of a screen displaying the sun.

The second verse finds her wearing a different black dress, and singing the song by many mirrors; simultaneously, visuals of Oh Land on the ground dancing appear.

[2] Other performances were at a Billboard promotional effort,[23] and three nightclub shows throughout New York City, immediately following the single's original release.