Marvel's The Avengers was a massive success with more than $623 million total earnings since its debut in 2012, according to Box Office Mojo data. Fans are expecting more developments for the upcoming Avengers 2: Age of Ultron movie, which is expected to initially hit the cinemas on April 2015 in Hong Kong.

New cast members have been added to join the Avengers line up, including Quicksilver and the Scarlet Witch, and already over recent weeks fans have been able to see leaks of the characters on set filming their roles.

Actors Aaron Taylor-Johnson and Elizabeth Olsen, who play Quicksilver and Scarlet Witch respectively, are included in the latest lineup of Avengers 2: Age of Ultron, and the choise of casting has excited fans, with both actors receiving strong positive feedback from superhero fans.

Taylor-Johnson divulged that he was at first hesitant to accept the role thinking that he would just be a small add-on to the already star-studded cast.

However, Director Jess Whedon was quick to correct the initial perception and told the uprising Quicksilver that the two new characters are not mere additions but also a huge part of the superhero group.

In other spoilers news for the upcoming film, which is sure to be a massive box office hit, Mark Ruffalo has revealed that he is working with CGI expert Andy Serkis - who played Gollum in Lord of the Rings - in giving the Hulk advanced facial effects.

In his Twitter account, Ruffalo confirmed: "@Captaian_jack Well, I have been working with the great @andyserkis on the big green boy and he is going to be even better than A1."

Serkis also worked on Star Wars Episode VIII, Godzilla, and Dawn of the Planet of the Apes.

The Avengers will battle against Ultron, a villain super robot portrayed by James Spader.

Below is a mock Avengers 2 fan trailer: