This was not good. I am on board with the whole beginning. It's heavy handed and clumsy at times with the meta commentary, but there is still something pleasant in this fictional ouroboros, inventing a "reality" that could inspire a fiction made of the events of the first three films. Having the memories of the characters be an important part of the plot is also an idea that works well when most of the spectators are ready for shots of nostalgia.
The belly of the film though is what feels like a whole hour of soporific exposition. It fleshens (even if it's with a lot of new categories of non-flesh entities) and complexifies the universe in an interesting way only to do just about nothing with it all. And then you have the overlong grand action finale which is well below the standards set in the previous three films and, frankly, below the current standards of the industry as a whole. It also does not help that the best action scenes in the movie are probably at the very beginning with Bugs, especially the Inception-inspired chase. These are not amazing, mind you, but within the confines of the film, these are probably the best. The worst is the fight scene in the train. Maybe it works on a small screen, but in a movie theatre this stuff is unwatchable (and I am a fan of nervous camera movements and editing in action scenes - when it is done well).
A failure, but at least a somewhat interesting one.