Marvel's "Avengers: Age of Ultron" has hit the web with a new trailer thanks to a Twitter campaign launched just over four hours ago.

Chris Evans, Robert Downey Jr., Scarlett Johansson, Chris Hemsworth and Mark Ruffalo are set to reprise their roles as Captain America, Iron Man, Black Widow, Thor and the Hulk respectively. James Spader, Elizabeth Olsen and Aaron Taylor-Johnson also join the cast as Ultron, Scarlet Witch and Quicksilver.

The trailer follows the release of a number of individual character posters over the last week.

"Avengers: Age of Ultron" arrives in theaters on May 1.