I've read a lot of very good reviews of this movie; the writers, the artists, and the voices are quite well established. But let's face it, DC has put out much more entertaining movies than this. The plot revolves around how would Superman spend his last days if he knew he was going to die. (I don't want to give anything away, since it is worth a rental if you get the special 'buy 2 get a third free.') In the process, he faces some uninspired villains I had not heard of and sounds bored constantly. And where's Wonder Woman and Batman --he's dying for pete's sake -- I know they would show up. Of course I have not read the book that this film was based on, so I suppose I can't blame the movie. However: even if one accepts the story as is, the execution just didn't catch my interest. Flat, flat, flat. Luthor was the only character who seemed to have any character. The one scene that I did find touching was Superman's return home. Yet, it came and went so quickly. I think that is the real problem here: the film was too compressed -- too much going on and there was too much to unpack. It made what could have been very emotional and touching rather unmoving; I didn't reach for the Kleenex once.
Bring him back and try again.