Aside from Ariel, every other actor was underwhelming. Really blah characters without much personality. Triton was just awful.
The new songs were all generic or bad.
Animals in the live action movies always fall flat because they just don't show the emotions like an animated film can do. Sebastian, Scuttle, and Flounder were all really meh.
They cut out the chef Louie song.
The CGI of Ursula at the end was just terrible.
The main actress did have a good voice and sung her songs well. That's about all I can say that was good.