noted that the group's slower songs were "probably their strongest suit", and thought that the song "manages to combine every element of the perfect Christmas ballad–a touch of elegance, a hint of romance, a soupcon of sexiness and a generous sprinkling of sparkle–and still finds time for a coy safe sex message". Whitney Pastorek of Entertainment Weekly said that it is "too slow, and the lyrics appear to have been written by a safe-sex-loving unicorn", adding that "it's almost impossible to identify the individual Spice Girls by their voices here, so airbrushed are the proceedings". A reviewer from Music Week rated the song five out of five, adding, "No turkey this as Spice Girls virtually guarantee a third chart topper and look a strong bet for the Christmas number one with a seasonally lush ballad. Anticipate much smooching 'neath the mistletoe." Time magazine's Christopher John Farley called it a "slumberous ballad [...] [that] seem[s] designed to amuse, titillate, ingratiate". In a review of the group's debut album Spice, Dev Sherlock of Yahoo! Music Radio called it a "glossy ballad that would do Mariah Carey proud". Chart performance "2 Become 1" was originally going to be released in the UK on 9 December 1996, but the release date was delayed to let Dunblane's "Knockin' on Heaven's Door"—a tribute to the children killed at the Dunblane Primary School in Scotland—to stay at the top of the UK Singles Chart. The single was released the next week, debuting at the top, becoming the group's third chart-topper and their first Christmas number-one single in the UK. It sold 209,000 copies in the first three days of release and 462,000 in the first week, becoming the fifth best-selling single of the year. "2 Become 1" sold 1.14 million copies in total, giving the Spice Girls their second and final million-selling single in the UK. Despite being released during the final two weeks of 1996, "2 Become 1" was the 5th best seller of the year and that year's fastest selling single of the year. In Ireland, "2 Become 1" was the group's second number-one single, and their first to debut at the top of the Irish Singles Chart. It stayed at the top position for six weeks, and became their first Christmas number-one single in the country. "2 Become 1" peaked at No. 3 on the Eurochart Hot 100, and performed similarly across the rest