My main disappointment is with the visuals, I think Arkham Knight looked better.
But outside of this... as usual I don't understand people. I thought this looked really great, the comparison with avengers are non sense, but it seems like it will be a forever running thing now, people constantly comparing every super hero games to avengers for some reason. It has an open world, it has stealth, actual missions and level design like the other Arkham games, and it looks like they even removed the levels on the ennemies (unless that's just for the video or an UI option), it just looks like an arkham game, but with the rest of the bat family and with optional coop, and that's really great.
But it seems like people decided to hate on this game since the beginning, just because it's not rocksteady and it's not about Batman, it's a shame that this project isn't allowed to exist for some people apparently, the concept is something I've been wanting since playing all the different heroes dlc episodes in Arkham Knight.