Videogirl on 11 November 2008
More or less 40 hours if you're very good (which means ending all your battles in less than 5 rounds), and if you go straight to the point skipping the skippable cutscenes (main story or reports) and without adding any skirmish or side battles.
But nobody can be that fast ^^
Edit : I confirm, I played for more than 15 hours to get to chapter 10 (had a hard time on the stealth mission of chapter 8 with Ty the Immortal who isn't really immortal after all). Oh and the good thing about VC is that you can save your game at any time during a battle and they can be pretty long sometimes (the Maximilian tank battle took me about 40 minutes to complete).
