TLDR: the movie is disjointed and contrived, good visuals can't make up for a lack of a good story. This was honestly two movies, an A plot for 2 hours and a B plot for 50 minutes.
I knew things were going south when they started jumping and staying in alternate universes, the first movie was good because it focused on the MC's struggles within one universe with occasional guests and plot devices from alternate universes. The multiverse was not the attraction of the movie, something they forget in the second movie as they jump through worlds without contributing to the characters or plot, the entire movie could've been skipped with just an interdimensional text conversation and a villain of the week cameo.
The B plot was the forgettable villain, who could've just been swapped with a janitor or receptionist within the same building without me noticing or caring-maybe its in the comic books but you shouldn't need to know the comic books to enjoy the movie. The villain doesn't challenge the MC's morality, they aren't related, nor was the villain foreshadowed or anything and they might as well be another generic villian. Then the villain disappears and we're treated to the A plot for the majority of 2 hours.
The A plot is that the MC is fighting against something declared non-canon within the movie- way to take me out of the experience with a contrived plot point. Never draw attention to the hand of the author, it takes the audience out of the experience and looks very clumsy.