Answer by taking a quote from the following article:

Shinee ( SHY-nee; Korean: syaini; Japanese: shiyaini; stylized as SHINee) is a South Korean boy group formed by S.M. Entertainment in 2008. The group is composed of four members: Onew, Key, Minho, and Taemin. Originally a five-piece group, vocalist Jonghyun died in December 2017. Shinee were introduced as a contemporary R&B boy group by their company with the goal to be trendsetters in all areas of music, fashion, dance, etc. and debuted in May 2008 with their first EP, Replay on SBS' Inkigayo with their single "Replay".

Prior to the group's debut, the label company, S.M. Entertainment, introduced an upcoming contemporary R&B boy group with its goal to be trendsetters in all areas of music, fashion and dance. The group's Korean name, Shinee is a new coined word and explained as a combination of shine meaning light, and the suffix ee, therefore meaning "one who receives the light". On May 25, 2008, the group's first EP, Replay, was released, which debuted at number ten on the Korean music charts and peaked at number eight, selling 17,957 copies in the first half of 2008. In May 2008, Shinee had their first stage performance on SBS's Inkigayo with their single "Replay".  In June 2008, the group won their first award, "Rookie of the Month" at the Cyworld Digital Music Awards, and were also awarded with the "Hot New Star" award at the Mnet 20's Choice Awards in August, 2008. In the same month, Shinee subsequently released their first full-length album, The SHINee World, which debuted at number three, selling 30,000 copies. Its title track "Sanso Gateun Neo (Love Like Oxygen)" is a cover of "Show the World" by Martin Hoberg Hedegaard, originally written by the Danish songwriting and production team of Thomas Troelsen, Remee and Lucas Secon. On September 18, 2008, the song won first place on M! Countdown making it the group's first win on Korean music shows since debut.  Shinee participated in the 5th Asia Song Festival, where they received the "Best New Artist" award along with Japanese girl group Berryz Kobo. The group attended the Style Icon Awards on October 30, 2008, where they received the "Best Style Icon Award". On the same day, a repackaged version of The Shinee World, titled A.Mi.Go, was released, which includes three new songs: "Forever or Never", a remix of "Love Should Go On", and the title track "Amigo". "A.Mi.Go" is a shortened version of the Korean phrase "Areumdaun Minyeoreul Joahamyeon Gosaenghanda", which can be translated to "The heart aches when you fall in love with a beauty".  In November 2008, Shinee won the "Best New Male Group" award at the 10th annual Mnet Asian Music Awards, beating fellow newcomers U-KISS, 2PM, 2AM and Mighty Mouth. In addition, the group also won the award for "Newcomer Album of the Year" at the 23rd Annual Golden Disk Awards.

what was the name of their debut album?
The SHINee World,