Sweet and sparkly cartoon with a few in-jokes for the adults

It sounds like every Hollywood rags to riches story ever made, because it's a classic tale.

Thelma the Unicorn is adapted from the popular children's picture book of the same name by Aussie author Aaron Blabey, and takes those themes of being authentic to yourself and turns them into a colourful and sweet animation.

The film is helmed by Lynn Wang and Jared Hess (of Napoleon Dynamite fame), with Hess and his wife Jerusha also taking writing duties.

It follows Thelma (voiced by Alabama Shakes frontwoman Brittany Howard), a small-town farm pony with big dreams of becoming a major music star and headlining the 'Sparklepalooza' music festival.

She's in a band with her fellow farm workers, donkey Otis (Will Forte) and llama drummer Reggie (Jon Heder), but their audition for the festival is over before it begins when the judges deem them to have the wrong look for music success.

Thelma, dejected, believes if she could just look like the popular but vapid star Nikki Narwhal (Ally Dixon) - a bit sparkly, impressive head horn - then people might finally pay attention to her.

So when she's unexpectedly doused in bright pink paint and silver glitter while pretending a carrot is a unicorn horn on her head, she leans into her new identity.

The fame machine quickly sweeps her up and she gets a skeezy manager in Vic Diamond (one half of Flight of the Conchords, Jemaine Clement) and a fake, content-creating boyfriend in Danny Stallion (Fred Armisen).

It's a simple story that'll be easy for kids to follow, with a pretty good message about not giving up what makes you you in order to impress people.

Otis tells Thelma right from the start that she's perfect just the way she is, but these appeals, of course, fall on deaf ears. Otis is the true hero of the film, but Thelma is flawed and relatable.

The soundtrack features a mix of familiar songs and covers, as well as some fresh content, many co-written by Howard and/or the other half of Flight of the Conchords, Bret McKenzie.

Howard has an incredible voice, which anyone who has listened to the Alabama Shakes already knows, and that gives Thelma's performances extra punch.

The comedy is middling, but might be enough to amuse younger kids.

Perhaps the most confusing aspect of the entire film is the fact that the animal characters and humans interact and seem to hold the same position in society.

Thelma is working on a farm, cleaning up manure that was left by some other farm animals. Superstars are just as likely to be from the animal kingdom as they are to be human. Again, kids likely won't care too much about this weird decision, but it's a strange one from an adult perspective.

For the adults there are a few little in-jokes, like references to artists called Patsy Swine and Smokey Buffalo. And there's a fun little nod to the Britney Spears-Justin Timberlake matching double denim situation of 2001.

The animation style is also a little disappointing. There's not enough character to the style, which, while technically proficient, lacks the kind of soul you'd like to see and backgrounds occasionally seem to lack depth.

Thelma the Unicorn is certainly not up to the standard of Netflix's best animated picture Oscar nominee of last year, Nimona, in either story or design.

The film could perhaps be likened to the less talented offspring of A Star is Born and Sing, partially raised by Ferdinand.