An improvement from the original in pretty much every way (full review inside)
GRAPHICS
The graphics are dated, but they still look nice, especially since its on a PS2, and you cant really expect to much from it (with exeptions ofc). The main difference i see is the Lack of the Fog of War in a way, in the first you couldnt see enemies if they were to far away, but the entire enviroment was like this also, which wasnt good. In drakengard 2, there is a greater draw distance for the enemy, and you can actually see the enviroment, which is always nice in a game.
Now, the dragon in drakengard was the best looking thing in the game, the dragon in Drakengard 2, is well, not as cool, its blue, and not red...so personally, i think it looks worse, but still looks pretty owning.
CONTROLS
The controls are WAY better than Drakengard, as you have control over the camera now! And there is 2 types of Melee attacks, and 1 magic instead of 1 attack and 1 magic, so the combat is a bit more varied now. The dragon combat has alos been changed slightly, but makes no real difference.
SOUND
It has a WAY better sound track, and the voice acting is a little bit better, and the sound effects are really good, so sound is one of its high points.
GAMEPLAY
Pretty much the same as drakengard, but with the addition of extra attacks, loads of ultra strong magic and combos, the ability to backflip(it looks cool, so hey, who cares if its a minor addition) 4 playable characters and your not fighting a lone all the time now, you got some allies to kick some ass aswell, instead of you being on your lonesome.
The dragon on ground missions also now has NEW magic attacks, instead of just raining down fire, it can ram its claws into the back of a giant, or fling enemies across the map etc. I think that this will play very similar to Lair in a way, but without the graphics and stuff.
OVERALL
Not much to say really, its basically the first game, but with some great improvements, and less of the flaws. And with a Kick ass story once again, you can hop back onto your dragon and kill some more guys in this great game. Ill advise you to buy the first one and play it before this one, as you wont no the story that well...even though they dont tie in EXACTLY, they do in some very small ways, that will help you understand what the hell is going on.