To be confirmed: seems that the mission needs to be finished under 7 minutes. 8:33 still gave me an A rank. Sab 14:37, 27 December 2008 (CST)
On B difficulty, 7:18 got me an S rank. So maybe the requirement is 7:30? - Sab
Could be 7:30. I'll go ahead and add that into the article for now and we can update as we narrow it down. Thanks for the info! - EspioKaos 10:37, 7 January 2009 (CST)