It is a game bred for a single purpose: to destroy the world of men.
LEGO LotR is made for two players -- this becomes very clear when, playing solo, a large chunk of the screen becomes dedicated to the "Press a button to join in!" prompt. Mission segments with parallel tasks, such as the Osgiliath mission where Faramir and the hobbits are on separate paths, also stick out more plainly. This being said, the game is still a blast to play by yourself, because it's just that cool. So find another LotR fanatic to play it with, if you can, but if you can't, just go ahead and play it, stupid! Go play it right now!
For being an edited adaptation of the films, the game's story is surprisingly lengthy -- it took me about ten hours from start to finish, and that's with a very minimal amount of veering from the critical path. So, roughly as long as the movies themselves. And the game's quirky combination of voice-acting gravitas and slapstick visual humor - like when Theoden, after the great battle outside Minas Tirith, gasps out "My body is broken," and then Pippin finds his minifig's leg piece - stays fresh for the duration.
LEGO LotR isn't a perfect game: I had a handful of technical issues - sometimes glitch-jumping up into the air, and a full crash once - and when you max out all the graphics settings, the simple-looking textures suggest that it wasn't really intended to play at more than 720p. And, yeah, the smash-everything-in-sight mechanic can get a bit tiresome. But there's so much variety, and so much awe-inspiring Tolkien (and Peter Jackson) shit in here, that the game's shortcomings are easy to forgive. I can't wait to spend hours and hours and hours unlocking more stuff.
Better than: LEGO City Undercover, The Lord of the Rings: The Return of the King (Mac, Mobile, NGC, PC, PS2, XBOX)
Not as good as: I dunno, if the game was more than two-player, or had higher-resolution textures? Point is, it's pretty damn good.
Also, there's a final bonus mission: where you play as Sauron (and player 2 as the Mouth of Sauron) and just wreck the shit out of a miniature version of the Middle-earth map. Badass.
Progress: Finished the story, 29.3% complete.