The more recent LEGO games have had large hub worlds that players can explore once they have unlocked enough of the game and LEGO Marvel's Avengers does not look like bucking the trend. TT Games are so proud of their new open world that they have even released a trailer highlighting the enormity of it.
Originally release for this year, LEGO Avengers has been pushed back to January 29th, which is no bad thing as we all have Fallout 4 we need to finish first before embarking on another massive world:
LEGO Avengers will set forth across more platforms than you can shake an Infinity Stone at and will have the two player local co-op that has made so many of the games in the series great fun to play with friends or family.