Minimum "in-game" hours to finish this game is at least 30 "Story mode" hours, because of one extra item in the shop that only appears then. ^^;
For Mission 9, the amount of boss parts to destroy for High Rank is roughly 30. I got 31 parts destroyed on that chapter, but you can do even more than that.
Last edited by VixyNyan; 02-20-2013 at 01:47 AM.