Saw this movie last weekend and thought it was painfully bad.
Way too many characters who were supposed to be clever but weren't too many layers of the story that didn't make a lot of sense (the portal - what the hell was the point of that) and though it should get credit for trying to have a plot it fell into the trap all of these superhero movies are in now of just having layer after layer of characters and battles etc as if these movies can't be succesfull without inane levels of multi-verse types of confusion.
And the interpersonal relationships between none of the characters were interesting or believable and the big narrative twist from the other movies that Superman was not sent to earth to do good but instead evil also wasn't developed in any meaningful way.
And the super dog and robots were just dumb as was the appearance of Supergirl or whatever it was at the end.
It did finish ok but the first half of the movie was really hard to sit thru.
But this guy has a much better review:
https://www.youtube.com/watch?v=bWpbv4hsZaI