Live Review: Katy Perry, Betty Who

Prismatic 3D glasses are handed out as we enter through the turnstiles, which adds excitement. Especially when the warning on the back instructs: "Not for extended wear, performing physical activity, outside play, driving or operating machinery."

Support act Betty Who is aptly named for this stage in her career. Dear Ms Who: If you're gonna wear a flirty mini, please dance like a lady. Actually, she's kind of borrowed Pink's look from the waist up. The front line - Who, her keys player and bassist - do some basic unison chorey during closer Somebody Loves You, but we wouldn't rave about the New York City-based Aussie.

When the majority of your fans haven't yet hit puberty, commencing half an hour after the advertised start time is unacceptable. And there's not even an acknowledgement/apology once Katy Perry arrives on stage to Roar. Her hologram scaled, Lycra, two-piece outfit is lined with LEDs that change colour, which is fun, but when the stage lights snap to blackout and flashing skipping ropes are utilised, we really deserve to see movement in unison. Cirque Du Soleil have raised our expectations when it comes to working with apparatus so if you can't nail it, cut it out.

Sections of the circular catwalk, which extends way out almost to the sound desk, are travelators and these are utilised to great effect. Pre-programmed vocals: "I'm wide awake." Perry screeches, "ARE YOU!?" And it's like an accusation, but we're only just warming up after the lengthy waiting period between sets. The band doesn't rise up from the bowels of the stage until after the photographers have been escorted out of the venue (song three). Pretty-coloured lasers abound.

Suddenly we're transported to Egypt and Perry rises up through a trapdoor on the main stage riding a puppet horse - it's so realistic! Dark Horse should be the opening of Perry's show. Now we're starting to invest. Like David Copperfield, Perry disappears and then reappears at the end of the catwalk; is it possible to move that quickly underneath the venue's floor? More travelators? An aerial prism contraption operated by three acrobats swoops down to collect Perry and carries her up in the air. She doesn't look fearless, or very graceful, and could work on her flexibility to create a better lines when of course these sections will be compared to Pink. "Yeah, and her feet weren't pointed," says my niece/plus one. Perry is certainly not a natural dancer. It's almost as if she's marking the routines and is often used as a human prop when lifted and manoeuvred around by her backing dancers. Remember Megan Washington's ARIA performance in 2010? Kinda like that.

"The way Perry breaks down all the syllables -"Un-con-di-ti-on-al-ly" - in the chorus irritates. And my 14-year-old niece yawns."

During I Kissed A Girl, which is given a much rockier treatment these days, her female backup dancers come out dressed as bizarre, bandaged mummies with ludicrously oversized padded butts and boobs. Two guitarists are strapped in and fly through the air while demonstrating their Nikki Sixx-style flame thrower axes (although theirs emit sparks rather than catapult flames). Random cat visuals take over the giant screens accompanied by Snoop Doggy Dogg's Gin And Juice. Tap dancing cats precede Hot And Cold then there's a portion of Vogue by Madonna, during which the cats strut around the catwalk. Geddit?

"Listen, I've changed since the movie," Perry claims after another of a gazillion costume changes. "I don't even have blue hair anymore, is that okay?" Drops hood. "I HAVE RAINBOW HAIR!" One selfie is granted to a chick holding up some kind of unicorn prop and continuing the theme through her headwear. Said fan is located in Perry's version of The Stones' Tongue Pit (the Reflection Section).

Perry's a smart businesswoman; she points out a t-shirt in the stands that's exclusive to her pop-up store, which has been set up at 1,000 Pound Bend in Melbourne's CBD. She then invites nine-year-old Dylan to the stage and instructs he must answer a few questions in order to score a pizza (including, "Who's your favourite singer?") What now? The One That Got Away. Through Prism Vision, the Unconditionally scene when punters wave their phones about and the butterfly puppets come out is impressive to behold, but the way Perry breaks down all the syllables -"Un-con-di-ti-on-al-ly" - in the chorus irritates. And my 14-year-old niece yawns.

Walking On Air is spectacular: Perry flies over the crowd while dancers cover the Reflection Section in billowing blue fabric to act out the song's title. Then Perry's raised up inside a ginormous yin and yang hoop skirt, which makes her look like a Barbie toilet roll cover. A selection of inflatables are navigated through the stadium: bottle of bubbly, handbag, Covergirl lippie (aka blatant product endorsement) and, hang on, is that the pile of poop emoji? Camera phones are put to work as heads shake in amused disbelief. Teenage Dream (as delivered by a 30-year-old), California Gurls - Perry finally delivers the smash hits.

Encore? (Hello, we're yet to hear Firework.) But first we endure Birthday and it's Laura's turn to sit in the birthday seat (which rises up and becomes a multi-tiered cake). And as Perry flies right by us sitting in a swing, as if lifted by the bunch of balloons she clutches, confetti canons explode and it rains multicoloured hearts and stars. "Time for Prism Vision, Time for Prism Vision..." Which prison. Oh! And, yes, putting the special glasses on makes the 'Firework's look awesome. Even better when you dance and move your head around (hang on, does that count as "physical activity"?) The prism prop closes with Perry inside. Houselights up.

Perry could not rely on more gimmicks and her Prismatic show could use a good edit. It switches and changes as maniacally as a sugar-fuelled toddler hogging the remote.