Katy Perry's new album "Prism" is supposed to be released on October 22 but the entire album can be listened to online and the critics have even started reviewing it now. The 28-year-old singer released the first single "Roar" sometime back and it has topped the charts ever since.

Perry recently appeared on "Jimmy Fallon" show and called "Prism" as an "evolution' which will be seen as a comeback for a more mature Perry who hasn't released any album since last three years.

"I think the difference between this one and this next one is that it's more vulnerable and raw and stripped down... It's an evolution. It's three years later and a bit more grown up, but still having lots of fun," Perry told Fallon.

"Prism" is the singer's fourth album produced by Max Martin, Dr. Luke, and Benny Blanco. Roar", "Dark Horse" featuring Juicy J, and "Walking On Air" are three singles officially released by Perry before the album.

Alexis Petridis, a columnist who writes for The Guardian, as reviewed Perry's album. "The single "Roar" is ruthlessly efficient in its bid to get the drunk and recently dumped member of the girls' night out party up on the table, using her WKD bottle as a microphone, and the rest of the album follows suit," writes Petridis.

"If the ballads are standard issue, the faintly trap-inspired "Dark Horse" sounds like a hit single, as does "Birthday" and, for better or worse, the new jack swing parody "This Is How We Do," he adds.

Celebrity blogger Perez Hilton is all praises for Perry's album and had unleashed a war with his best friend Lady Gaga when he praised Perry's single "Roar" and ditched "Applause" by Gaga.

"The exotic and erotic sounds of the new track were some of the best foreplay we got from the Prism preview, but now we want the whole thing!" Perez says in the new reviews.

Katy Perry's full album "Prism" can be heard here. Do check out the tracks and let us know your views.