The game does get better than more you play it, I'm really enjoying it now. I find myself playing as the Archer and Warrior. Never touch the Mage or the Scout. Infact, the sneaky Scout cunts piss me off more than the Mages do now. And playing as Evil on the Shire and just seeing the Balrog killing the last gang of Hobbit Archers was poetry in motion. Very much looking forward to the full game. Unless its two separate levels, as I understand it you'll be able to go up much further into Minas Tirith, I think those barricades at the top are makeshift for the demo. Learning not to take the game too seriously, and just viewing it as fun is the key.
Infact, what I'm now most pissed off about is Pandemic's apparent choice to only use music from the original one-disc releases of the soundtracks, rather than the more recent, complete recordings releases. I hope it is just for the demo, otherwise they're probably missing out on something like 6 hours worth of music. And this includes some of the best action pieces from the trilogy - the Prologue, full Amon Hen, tons more Helms Deep music, the full siege of Gondor, Pelennor Fields, and, most significantly, the Ride of the Rohirrim.
And the demo is now out on XBox marketplace.