Pop icon Britney Spears' new 90-minute Las Vegas show, "Britney: Piece of Me," at Planet Hollywood Resort & Casino drew raves from the sold-out crowd of A-list celebrities, reporters, die-hard fans and family members.

Spears, 32, announced her two-year deal to perform her own show on ABC's "Good Morning America" on Sept. 17 and had just four months to put together the performance. Spears signed on to perform 50 shows each in 2014 and 2015 at The AXIS Theater, and casino executives told the Associated Press the gig could be extended if it proves a success.

(Credit: Denise Truscello )

It's no surprise all eyes are on Spears. With the release of her eighth studio album titled "Britney Jean," her 32 nd birthday and learning choreography for the 24-song set list, Spears has no doubt had a very busy December.

E! premiered its two-hour documentary titled "I Am Britney Jean" on Dec. 22, which it said would let fans take "an intimate look at one of the most overexposed yet under-revealed stars of today as she faces one of her biggest challenges ever while finishing her album, shooting videos, doing press - and being a mom."

The documentary also served as a promotional tool for Spears' Vegas residency, giving fans an all-access behind-the-scenes look at Spears and her army of backup dancers prepping for their routines and all the other intricate details in putting together such a large-scale, high intensity show.

Even Planet Hollywood welcomed Spears with open arms to her new home with an homage performance to some of her biggest hits during a staged event in front of the property earlier this month.

So far, Spears' whirlwind publicity schedule (thanks perhaps to her revamped management team) seem to have paid off with opening night fervor.

Katy Perry, Miley Cyrus and Selena Gomez were in attendance, along with DJ Pauly D, Adam Lambert, and "Extra" host Mario Lopez. Cyrus was seen enjoying the show in various Instagram posts including one in which Cyrus is seen alongside Spears' mother and sister.

Spears tweeted out her thanks to her celebrity friends.

Soy excited to see @britneyspears baby bottle pop it off tonight at her grand opening @phvegas! We are coming in full lewks to support! ???? - Katy Perry (@katyperry) December 28, 2013

. @KatyPerry Was SOOOO good to see you again girl! Glad we could make our Vegas date happen :) - Britney Spears (@britneyspears) December 28, 2013

. @MileyCyrus Love you so much! Thank you for coming to #PieceOfMe! I adore you :) - Britney Spears (@britneyspears) December 28, 2013

Lopez tweeted about his good time at the concert especially getting plucked out of the crowd by Spears to join her onstage for a dance number.

Mario Lopez posted this photo to Twitter on Dec. 28, 2013, "Somehow ended up on stage w/ @BritneySpears in bondage & getting spanked by her... :)"

The show takes place in a relatively intimate theater, as opposed to the large-scale venues and stadiums where Spears has performed her tours in the past. Spears performs most of her greatest hits off her older albums from her 15-plus years in the business and even recycles some of her classic choreography. "Perfume" and "Work Bitch" were the only songs featured off her latest album.

"'Britney: Piece of Me' is the most cutting-edge pop concert experience ever produced for Las Vegas, featuring a four-piece band, 14 dancers, elaborate sets, unforgettable costumes and state-of-the-art, never-before-seen technology," said a press release from Planet Hollywood.

"The AXIS is part nightclub and part theater, setting it apart from any other venue in Las Vegas," the press release reads. "The 4,600-seat, intimately-sized theater allows Britney's fans to see her as they've never seen her before."

(Credit: Denise Truscello)

So far, early reviews have been positive for Spears' lavish, entertaining spectacle.

"Spears stomped into town with a 21-hit salute to her 15 years of dance confections the artfully melded spectacle with stagecraft," USA Today writer Marco della Cava wrote in his glowing review.

"In fact, listening to some of the more empowering songs that helped close the show, including 'Stronger' and 'Till The End of the World,' one had to acknowledge that all three pop divas in the audience this night owed a huge debt to the mother of two on stage," Della Cava continued. "She may not be the 18-year-old girl next door who shocked the world silly, but she's still a force to be reckoned with."

MTV News writer Sophie Schillaci, who took over MTV News' Twitter account to live blog the night wrote: "True to her word, Britney Spears poured on the cheese during the opening night of her "Piece of Me" Las Vegas residency," referring to Britney's statement that "cheesy is good" from her E! documentary.

"Spears delivered on her signature style of larger-than-life production, blaring beats and rapid-fire dance moves, whirling through seven costume changes and even a couple of wig changes," Schillaci said.

Schillaci posted an Instagram snippet of "Me Against The Music," which featured recycled choreography from her music video.

"The show's production values are unusually high for a casino residency, often calling to mind the golden age of music videos," said Hannah Dreier of The Associated Press. "Its high-concept set pieces featured a cadre of backup dancers who danced in human-sized hamster wheels and somersaulted over the Grammy-winning star."

Billboard writer Keith Caulfield kept a live blog running of the show, and mentioned the thrill of hearing Spears "breathing into the microphone," in reference to the question of whether there were any live vocals in the show.

"Notably, 'Me Against the Music' was one of the few songs during the show where hints of Spears' live vocals were audible," Caulfield wrote. "(Though, she was still singing over the original studio vocals of "Me Against the Music.") The vast majority of the show was lip-synced, and only occasionally were any seemingly live vocals heard."

Spears has maintained that she only plans to sing live during her residency. Spears told Chicago's 103.5 KISS FM, "I'm definitely going to be singing live. I always sing live. It doesn't sound so great all the time, but I do my best."

Spears' manager Larry Rudolph told Billboard in September there's not a single artist who can dance full out during a song and sing without a vocal track underneath them.

"The idea is to try to get her pretty close to 100 percent. There might be some numbers where she's full out dancing with a (vocal) track underneath her, but there won't be any lip-syncing across the board on anything," Rudolph said.

Regardless of any controversy that may surround Spears' residency, her Vegas engagement is setting a precedent. The Los Angeles Timescalls it a "gamble," writing, "It's unparalleled for a contemporary, major Top 40 pop act to embark on a long-term Vegas engagement while they're still on the charts- and on the playlists of people under 35. "

However, leave it to Spears to take on the challenge. Few doubt the resilience of Spears' fans, who will continue to flock to see her make history in Sin City.

Spears continues her residency with a show on Dec. 28, followed by shows on Dec. 30 and Dec. 31. It then takes a break until Jan. 29. Tickets range from $59 to $179.