The game was created by Chunsoft and released by Sega. Nasu (the main writer at TYPE-MOON) wrote a chapter of that game and Takeuchi ((the main designer at TYPE-MOON) did the character designs only of that chapter (the rest of the cast are real actors). CANAAN will take place after the events in that chapter.
Nasu wrote the story for the game 428, and this is pretty much the animated version off of it, so yeah, kind of. i'm not sure if Nasu is going to help work on Canaan though.
Nah, this will be different. Chaos;Fail was a Madhouse's anime. This will be a PA Works' anime, with Ando Masahiro (Sword of the Stranger) as the director.