Well, it's hard to elaborate without spoilers. I will say the main thing was as Shilsen said. The blandness and sheer lack of acting. The whole movie was basically one event-->skip (possibly a few years)-->event-->skip, repeat ad nauseum. The plot, even though history provided such a rich framework to work with, was very thin, each strung along event very loosely tied together, and what should have been emotional scenes were entirely lacking. Jamuhka meets Temujin, and within one minute of film time, they're sitting by a camp fire, cutting their hands to become blood brothers. What?!
The film was supposed to be based around the relationship of Temujin and Borte, yet they spend very little time together, and when they are together, the conversation includes lines to the effect of "You will make a good wife." "Yes, I'll make a good wife." It's possible the translators just kept things basic so rabid "japanese is always better" type anime fanboys wouldn't scream bloody murder at them misinterpreting what was said, but...I hate it when subtitle writers play it safe like that.
Now some stuff that has to be in spoiler blocks:
[sblock]1. The way things were sped through was just so sloppy. At one point early on as a kid, he runs off to pray in a yoke, and then the next second he's out of the yoke. Is this him coming back later on once free? Towards the end, he basically leaves what seems to be his first bit of happiness the whole film, with his family, after havingn ot seen them for like ten years, riding off to basically bend all of the Mongols to his will for their own good. How wild-western. *eyeroll* Of course, the next scene is years later, the army having been assembled, and battle about to be joined. After the initial wave of the enemy is defeated, the rest charges, and a thunderstorm starts. All the Mongols cower out of fear, except our hero, who rouses his men to their feet. Instead of showing them winning, the filmaker just lets us assume they walked right over the huge enemy army, cutting to Temujin victorious. We don't even get to wait to the second film to see that smug Tangut ruler at his feet, the conquering of that area is covered with...a text description! Movie's over now, great ending, huh?
2. The portrayal of Borte, and how it affected his portrayal. Look, I knew his first child was likely not his, and she was raped by Merkits. But what the film did for the second child was just inexcuseable! It's implied that she sells her body to a merchant in order to ride to where her husband is held, to free him. Maybe the writers thought this would be a great show of devotion. To me, it just made her look like a whore, partly cause there was little to no anguish shown when she made the deal. Just a simple "you know what my payment will be," end scene. As for Temujin, he just looked so pathetic, riding away in the cart, as she said, "This is your daughter." Poor guy. Again, I wouldn't be so angry about it if it weren't for the fact this didn't actually happen, and the filmaker made a concious effort to put it in, because he thought it would improve the plotline. That's what makes me mad.
3. The whole Jamuhka thing. Not only was their meeting terse, later on, they fumbled the chance to show the emtional anguish as Temujin had to let him be executed (his wish), rather than let him live and join like he had wanted. Not only is this touching moment completely missing, they even decide to alter history and have Temujin let him run away! All I can say is, that better be for a dramatic scene in the next movie, but...since the end fast-forwarded past the point Jamuhka should have been killed, I doubt it.[/sblock]
For what I liked? The costumes were great, and while i'm not sure of the authenticity of the arms and armor the Mongols wore, it certainly looked cool. The battle scenes were great to watch when there was actual fighting. Well choreographed, and lots of blood. I said before, I'm in love with the soundtrack, and it was good in the movie. The backdrops and scenery were top notch, I probably could have sat there for two hours just looking at the pretty pictures.
Overall, on such a small budget, the movie was done very well, and I commend them for that. However, all these good points pale in comparison to the bad, and while this may actually be worthy of "mediocre" instead of outright terrible, I can't recommend it to anyone who isn't a diehard Genghis Khan fan. On the other hand, my fiance knew nothing about him before the movie and actually seemed to enjoy it more than me, so perhaps going in already knowing the history is a hindrance to enjoyment. Which...really isn't a good trait for a film based on historical characters and events...