After being announced years ago, the first full trailer for Marvel's Avengers has finally been unveiled by Crystal Dynamics, Marvel Games and Square Enix.

In the trailer, which was revealed during Square Enix's E3 press conference, Marvel's most iconic heroes team-up to defend San Francisco as the team celebrates the opening of its west coast headquarters.

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After a brief fight on the Golden Gate Bridge, the trailer reveals that a Terrigen Reactor aboard the Avengers' helicarrier malfunctions and causes mass destruction. In the ensuing fallout of "A-Day," the Avengers are outlawed and the team is officially disbanded. Five years later, a new threat forces the team to confront the demons and reassemble.

As the trailer shows, Iron Man, Hulk, Black Widow, Captain America and Thor will be playable characters on launch. The press conference revealed that the game will feature a growing roster of playable characters through free subsequent DLC. Hank Pym will also make an appearance, although it's not clear if he'll be a playable character too.

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A few classic Marvel villains, including Taskmaster and the Abomination, also made brief appearances in the trailer.

As revealed in the press conference, the game will feature an all-new original story, single-player and multiplayer gameplay and free updates for "years" to come.

Featuring Nolan North as Iron Man, Troy Baker as Bruce Banner, Laura Bailey as Black Widow, Jeff Schine as Captain America and Travis Willingham as Thor, Marvel's Avengers will be released May 15, 2020 for PlayStation 4, Xbox One, PC and Google Stadia.