Differences between this and original?

[Chip]

So is it the same thing with a new coat of paint or am I missing something?

[Harouki]

Nightmare is a new scenario dealing with an army of goblins, skeletons, griffons and dragons attacking human kind led by some mysterious force.

The player character can control these new units which are added to the various books of the original Hundred Years War scenarion (which is included in this game.)

Weapons have been balanced out with new weaknesses and strengths and new abilities like how the Long Spear (Pikes) can now manual attack instead of solely relying on the Brace manuver.

The main thing is that you can now combine mercenary squads (once you have the ability to deploy more than one) to have even more units to command. Like right now, I can deploy 3 mercs, my main one and 2 friends. The main one is using Lady Lancers, the second merc is using Pikes, and the last one is using Rapiers. If you are using a controler you can combine your squads by holding R2+X/RT+A to increase your squad size and include multiple different squads. By pressing R2/RT you can swap between the leaders of the squad so you can switch from Lancers -> Pikes -> Rapiers.

You should check the wiki for more info, really.

http://koei.wikia.com/wiki/Bladestorm%3A_Nightmare