Lisa-Marie Ferla's verdict: four stars

Fears that Katy Perry's new tour would embrace the darker sounds of last year's Prism album proved unfounded as soon as her army of neon-clad, spear-slinging pharaoh backing dancers started playing jump-rope.

Dubbed 'Prismatic', the show took its motif seriously from the moment a giant pyramid rose up out of the ground with its star inside.

But there was plenty of space for ridiculous costumes, light shows and even an entire segment featuring a pink cat-suited Perry prancing around in front of a video backdrop of anthropomorphised cats.

Dressed in a light-up tennis skirt with matching hair extensions, Perry began the show with high energy and beat-heavy rewordings of "Roar", "Part of Me" and power ballad "Wide Awake", interspersed with shouted platitudes about "loving yourself" and "forgetting your Instagram".

The whole effect was that of a cross between a warehouse rave and an exercise video from the 1990s, and just about as soulless.

That was until the props came out: a giant mechanical horse in Egyptian head-dress for "Dark Horse", mummified dancers camping it up to "I Kissed a Girl" and a spaceship sturdy enough to hold three dancers and stage a mock-abduction during "ET".

Raps by Juicy J and Kanye West were piped in accompanied by cheesy onscreen visuals, but the effect wasn't enough to spoil the fun.

Still, Perry was at her best when the fireworks were turned off, giving her time to interact with and charm the crowd in her Little Pink Riding Hood dress. Prism closer "By The Grace of God" was performed beautifully with just a piano and backing singers, while a self-accompanied acoustic guitar version of "The One That Got Away" was an easy highlight.