There is a remix of "Scream & Shout" that features Lil Wayne, Hit-Boy, Diddy and Waka Flocka Flame.

Other guest appearances on the album include Afrojack, Juicy J, Chris Brown, Miley Cyrus, Skylar Grey, Nicole Scherzinger, Korean pop group 2NE1 and will.i.am's The Black Eyed Peas bandmate apl.de.ap.

will.i.am confirmed that he collaborated with Britney Spears, Demi Lovato, Jennifer Lopez, Cheryl Cole, Nicole Scherzinger, David Guetta, Kesha, Alicia Keys, Swedish House Mafia, Rihanna, Shakira, LMFAO, Eva Simons, Chris Brown, Mick Jagger, Busta Rhymes, Swizz Beatz, Miley Cyrus, Justin Bieber, Avril Lavigne and Ne-Yo – but not all the artists collaborated on the released version.

[8] The event was attended by Lindsay Lohan, Meagan Good, Nicole Scherzinger, Steve Aoki, Wilmer Valderrama, Corey Feldman, David Faustino and many others.

Along with a medley of #willpower songs and "This Is Love",[11] he also performed notable remixes of Gotye's 2011 hit single, "Somebody That I Used to Know",[11] and Kanye West's "Mercy".

[17] The music video for the song, part of which was shot on London's South Bank, with Tower Bridge in the background, premiered on May 25, 2012.

The track was released in the United States on June 19, 2012, officially impacting Top 40 Mainstream radio, and being promoted with a performance on America's Got Talent.

It features Spears chanting in a British home counties accent, and a sample of the famous 'Britney, bitch' hook from her single "Gimme More".

[21] At the end of January 2013, a hip-hop remix of the song featuring Lil Wayne, Waka Flocka Flame, Hit-Boy and Diddy in addition to Spears was released.

"#thatPower" featuring Justin Bieber was announced as the third single from #willpower on March 15, 2013, via will.i.am's official Twitter account.

"Feelin' Myself" featuring Miley Cyrus, French Montana, DJ Mustard and Wiz Khalifa was released on November 26, 2013, as the lead single for the re-release of #willpower.

After lower performance, the song wasn't set to be included in the album and it was replaced by "This Is Love" as lead single.

[30] "Fall Down", featuring vocals from Miley Cyrus, was released as a promotional single on April 16, 2013, as part of iTunes Countdown to Willpower.

[46] Andy Gill from The Independent gave the album 3 out of 5 stars writing the album is "stuffed with sounds that, while in no sense as cutting-edge as he likes to make out, crest the wave of the popular" and compared it to the work of other artists such as David Guetta and Swedish House Mafia.

[38] Stephen Unwin from the Daily Express also gave the album 3 out of 5 stars writing that will.i.am "alongside enjoying a play on words, gets kicks out of collaborations.

"[42] On a more negative note, Kevin Liedel of Slant Magazine called the album "a slog of pop clichés and self-absorbed preening", criticizing how "every track can be boiled down to a handful of catchphrases, a fuzzed-up club beat, and some sort of glitchy, mid-song breakdown".

[44] Controversy arose due to identical segments present in the song "Let's Go" and the track "Rebound" by Arty and Mat Zo.

Arty claimed on Twitter that Interscope Records failed to ask permission from Anjunabeats before sampling "Rebound".

[47] Anjunabeats later released a statement that although Arty was credited in the sleeve notes, this is not a valid form of obtaining permission to use the sample.

I got in touch with Arty and showed it to him, did a different version to it 'cause I asked him [to] make it newer 'cause I don't just wanna take your song and rap over it.