The album's first single was announced to be "Heaven Can Wait", in September 2009 it peaked at number 18 on the BillboardHeatseekers Songs chart and at number 32 on the Pop Songs chart. Actress and singer Demi Lovato was also announced to be contributing guest vocals on album's song "We'll Be a Dream" which is the second single off the album. The band undertook a tour of the United States to support the album.
The artwork for the album was released on November 8, 2009. Following the release of a false track listing in October, the official track listing was announced on November 17, 2009. The album was also originally scheduled to be released on November 17, but was corrected to be released on December 8, 2009. Pre-orders of Smile Kid were available in two different packages. The album was uploaded for streaming download on MySpace on December 8, 2009.
Alternative Press reviewer Evan Lucy rated the album 3/5, saying that "Fans of We the Kings' debut will undoubtedly find something to hold onto with Smile Kid, but for those who were less than enamored with the band's pop-punk blend will likely stay that way." He said although the band "have expanded their previously narrow sound", he was still dissuaded by the band's failure to branch out musically; "Until the band are willing to step outside further outside the musical box and Clark is willing to belt it out, We the Kings will remain good, not great--and still on the verge of pop-punk royalty."