Ok watched it last night when it came out on HBO Max.
First I is obviously designed for big screen for full effect. The CGI and all is great, Monster Battle scenes great, I won't give spoilers yet.
The Story could have been flushed out more, too much Human stuff that was seemingly way unnecessary and dragged things down. The whole motivation part of the story was pretty late in coming to fruition also, and resolution seemed to fast for a whole movie to be built around.
There was also some reaches in feasibility which I can't elaborate on without spoilers.
There was not enough real Monster interaction for a movie named as a prize fight, even the secondary Monsters had little time and were a blip.
Not sure if it was just cost but King of the Monsters had a lot more to see concerning the Titans versus this movie.
That's a quickie overview.