Help sniffing Metal Assault files (Metal Slug clone)

I was hoping one of the wizards here would have more luck finding art inside Metal Assault archive file.

Metal Assault was a nice online Metal Slug clone game that was published by aeria for english speakers, it was cancelled a few years ago, so I wanted to see if some of the nice art in the game could be salvaged.

This is the only container file that the game client has:
https://www.dropbox.com/s/9or36o7e8bav7rg/mas.cvf?dl=0
the other files are in the client are just .dlls and small .exes.

I tried scanning the file using watto game extractor, ravioli game tools and dragon unpacker, neither picked anything.

Aluigi's offzip manages to extract a huge amount of .dds and .tga files, which correspond to character textures and equipment icons, I was hoping someone wise in this stuff would manage to pull out the backgrounds and sounds too.

This post of Xentax:
http://forum.xentax.com/viewtopic.php?f=10&t=6628

has some analysis of the file's structure, and given the comment I guess that the guy was able to unpack the whole thing using offzip; but the truth is that what the guy is talking about regarding file structure completely eludes me, no idea how to use the info for extracting the files.

Any help appreciated.