"Marvel’s Avengers begins at A-Day, where Captain America, Iron Man, the Hulk, Black Widow, and Thor are unveiling a hi-tech Avengers Headquarters in San Francisco — including the reveal of their own helicarrier powered by an experimental energy source. The celebration turns deadly when a catastrophic accident results in massive devastation. Blamed for the tragedy, the Avengers disband. Five years later, with all Super Heroes outlawed and the world in peril, the only hope is to reassemble Earth’s Mightiest Heroes."
As was previously reported, Avengers will feature both single-player and co-op gameplay. The five characters that will be able to be played as include Captain America, Hulk, Iron Man, Black Widow, and Thor.
Square also said on stage that this is a game that they want to support for years to come. Over time more content will be added but it will all be entirely free.
Last but not least, it was also divulged that Marvel’s Avengers is set to arrive on Xbox One, PS4, PC, and Google Stadia next year on May 15, 2020. Excluisves content for PS4
EDIT: New characters and regions will be free, and that there won’t be any loot boxes.