In his weekly UK chart commentary,
James Masterton wrote, "The follow-up has been a long time in coming but has been well worth the wait, belying the
soap origins of the singer. Radio loves it to death, hence this high entry and I would be very surprised if this does not scrape a Top 10 placing." He added, "Its the kind of single that grows on you with each play". A reviewer from
Music & Media commented, "Like tea-for-one, there's now also
new jill swing for individuals. The radio mix is the sweetest, but the
West End mix is far more adventurous and memorable." Alan Jones from
Music Week wrote, "Penned by
Narada Michael Walden and
Preston Glass, it's quite odd with some ill-advised spoken segments alongside the better sung parts. It never gets into overdrive, but will still be a hit."
Emma Forrest from
NME viewed it as "disconcertingly cheery". Female pop-punk music duo
Shampoo reviewed the song for
Smash Hits, giving it a score of two out of five. Rob Pendry of
Swansea Sound called it "excellent" and concluded that "Sweetness" set a "great future" for Gayle, proving she could branch out from her acting career. In 2012, the
Official UK Chart named "Sweetness" a "pop gem" and a "sparkling piece of sheer pop brilliance". ==Music video==