But if the Hobbit is worth four stars (from a possible five); the Return of the King (RotK) is worth no more than two stars - and is a shambles all-round.
It could be said that it was an impossibility to make a really good movie from just the second half of LotR (the first half having been already made for cinema in the horrible Ralph Bakshi version of 1978; a film which I disliked so much that I will neither be re-watching, nor reviewing, it!). But even making all allowances, RotK is unenjoyable and unsuccessful in all important respects.
On the plus side - the animation quality is much better than with The Hobbit of 1977 - albeit there is a very irritating and unconvincing overuse of a technique of 'shaking' alternation of pictures, back and forth between two images, and supposed to represent something like anger or fear.
And there are a couple of good pieces of music- one lovely melody reused from The Hobbit and applied to the Gray Havens departure:
And the legendary/ notorious 'Where there's a whip' is just a terrific song!
I don't think it is worth describing in detail the changes made to the story to accommodate the story - in a nutshell, the story is done as a flashback with the conceit of its being told to some of the Fellowship back in Rivendell after it is all over by a minstrel from Gondor. Not many of Tolkien's own words are used - and the dialogue often seems vulgar and inept.
The bulk of the depicted story is focused on Frodo and Sam escaping Cirith Ungol and then walking through Mordor to the Cracks of Doom, which makes for a miserable, visually-dull mood.
The most bizarre scriptwriting decision was to take Frodo to the point of claiming the ring and standing on the brink of the volcano - then having him go insane and get lost in the Cracks of Doom with Sam (and Gollum) searching for him for many days; until the Army has arrived from Gondor at the Back Gate...
The RotK of 1980 is not an actively-unpleasant movie, but it is just a waste of time to watch it except as a curiosity.
Eowyn and the Witch King is pretty good:
And at the very end, there is a very appealing notion from Gandalf, in response to a question about what will happen to hobbits in the future: he points-out that Frodo is taller than Bilbo, and Merry and Pippin taller than Frodo - and that Hobbits seem to be turning into Big People and blending with men - and he finally 'turns to camera' with an aside that some Men of the future (implicitly those watching the movie) may have more than a little bit of Hobbit in them... Nice!