I think it's fair to criticize that there wasn't any gameplay footage, so it's questionable to me that less than a year from release that they don't have some sort of gameplay example.
Having said that, I love the in engine footage that was shown. I love the premise, I loved the character design, I love the fact that this is not a rehash of the MCU. These characters have existed for decades with different style story telling, some good some bad, but the world has really come to know the Avengers from the movies, so I think it's great to give young people an experience that is outside that, as most people don't really read the comics anymore.
Yes there's a lot that really leans on the movies, the character design is very MCU 'esque but enough differences to make it unique, except for perhaps Banner that was pretty much straight lifted from the MCU. Yes the team is the original MCU Avengers sans Hawkeye, but I liked the way it was presented.
I think the voice cast, from the ones I know is excellent. Nolan North is well known for his work on Assasin's Creed and Uncharted. It looks like a lot of thought and time when into the creation and story telling in this game. Will it work out? That remains to be seen, but I like what I've seen so far.