Scarlett Johansson thinks 'Avengers: Age of Ultron' is ''Shakespearean''.

The 30-year-old actress - who reprises her role as Black Widow in the latest instalment of the Marvel franchise - believes the film is different from any other superhero tale because of its complex plot.

She said: ''There's a Shakespearean aspect to the story that Joss Whedon has crafted - particularly with the villain Ultron.

''His artificial intelligence is created by Tony Stark to protect humanity, but because Ultron's born of Tony's ego, he's tragically flawed.''

And Scarlett found the movie particularly exciting for her character.

She told NME: ''Black Widow has experienced a lot of trauma and never been able to make active choices for herself, but now she's ready.

''I'm looking at it as an actor, looking for material that's substantial.

''So when you're shooting a page of the script over two weeks it gives you something real to hold on to.''

The blonde beauty added she would love to star in a stand-alone Black Widow movie.

She admitted: ''A Black Widow movie would be cool. I'm always happy to put the catsuit back on.

''From your lips to Marvel's big-pocketed ears...''