Okay, I've had a chance to look at some files on the disc. Unfortunately, there's not really anything exciting to tell.
They've changed the file structure quite drastically. Gone is the xbox compression system used for SC4, and now everything are in big container files. It's called CPK and it's apparently used in many other games. It's possible to extract files, but some info is lost, like the filenames for anything. Which makes it a pain to find stuff, and as far as I know, there's no way to replace files with modified ones, which limits modding greatly. Savegame hacking might still be possible, but I can't look into that.
Anyway, now for some actual information:
-In the executable there's a list of strings of names as they're referenced by some of the code. The new characters added since SC:BD are (as written in the file and in the order they appear):
ZWEI
VIOLA
PYRRHA
EVIL PYRRHA
PATROCLUS
TRUTH PATROCLUS
NATSU
XIBA
LEIXIA
AEON
YOSHIMITSU2
ELYSIUM
MASTER KILIK
BOSS ASTAROTH
BOSS CERVANTES
BOSS NIGHTMARE
DEVIL JIN
GUEST1
GUEST2
The most interesting thing is that Ezio isn't mentioned by name, and instead there's 2 guest slots. I guess they considered having another guest at some point?
-Looking through character select screen textures, there's all the obvious characters. The known roster and of course Dampierre. There's no other characters waiting for an unlock key. I can't go through movesets, but I'm willing to bet there's nothing hidden there.
-This mysterious texture with Japanese text. I have no idea what it says, and whatever it does say is probably extremely trivial, but I'm curious anyway. Edit: Apparently it's just some generic warning regarding copyright infringement.
Aaaaaaaaand... that's it basically. I haven't looked at all the files (and it's a bit of a hassle to go through without a proper file structure) but I don't think there's anything interesting to find.
