While Marvel's Avengers was showcased behind closed doors at E3, Square Enix and Crystal Dynamics have not yet released lengthy gameplay footage to the public. Yesterday at San Diego Comic Con, they showed a similar demo to those attending the Marvel Games panel in Hall H. Even though no one was supposed to record, that did not stop some members of the audience. Earlier today, PS5 Intel and u/THEPROMISE102 leaked parts of the demo on YouTube and Reddit, respectively.
In case did not know about this demo, it takes place on A-Day, a Fourth of July-esque celebration of the Avengers. Unfortunately, the Golden Gate Bridge is attacked by Taskmaster and some mysterious soldiers, and the five most notable Avengers have to team up and take him down. In the first video you can see below, gameplay of Thor, Iron Man, and the Hulk is shown.
I saw the demo in person at E3 2019, and can confirm this is basically the footage they showcased there with a few minor tweaks. DualShockers' Logan Moore was ultimately underwhelmed by the demo, and you can check out his impressions. Below, you can also watch the second part of this video via Reddit. It features more Hulk gameplay as well as our first glimpses of Black Widow and Captain America.
Part 2. SDCC. Sadly the last part. Security almost caught me. from r/MarvelAvengersProject
Even though these video are not of the highest quality and may be taken down soon, they are going to be the best glimpse of Marvel's Avengers that we will likely have publicly for the next month. During the San Diego Comic Con panel for Marvel Games where this was revealed, Square Enix confirmed that the gameplay will not officially be released by Square Enix until a week after Gamescom in August, similarly to how CD Projekt Red is handling Cyberpunk 2077's E3 demo.
As soon as Square Enix officially releases the demo, DualShockers will let you know. Marvel's Avengers is slated to release for Google Stadia, PC, PS4, and Xbox One on May 15, 2020 and can be pre-ordered on Amazon right now.