Both guides above are fantastic, but I just wanted to add as a general rule of thumb:If you complete all the missions required
(Deja Vu is not necessary) 100% stealth with no kills (1 level being an exception), no reflex on, next to no checkpoint abuse in a relatively quick amount of time, then you will get the S rank.
I know that may sound like a lot, but the fact is this game is one map that, once effectively learned, can be a breeze to run through no matter what the objective. So learn the map
- complete a few runs on the mission, understand the enemy patrols, and steer clear of high guard concentrated areas, and you will be fine.
The only one I had difficulty with was the Jamais Vu mission, and time was my enemy. I would take too long
and despite not having any alerts, kills, or reflex, the time would kill my S Rank and drop me down to an A.
I found with that mission you need to no more than 12 mins - if you are taking longer than that, then no matter how amazing you did with the rest of it, you would not get the S Rank.
For Ground Zeroes, I took a while just because I was trying to mark everyone. Ended up with an S Rank by accident. Just stayed stealth, rescued all 7 POW's, killed no one and kept it under 40 mins.
The Classified Intel Acquisition was the easiest for me, and you can get it done with no kills and stealth in no time at all. You can follow the very simple guide for this achievement
The Intel Operative Rescue was much easier than I anticipated as well, as long as you go for the pacifist
achievement, and do not abuse checkpoints.
Eliminate the Enemy Threat was the only mission where I just straight up killed people (the two marks in question). If you go for the depth
achievement, and do well enough to get (I believe) a A rank, then you will have a sniper rifle from the mission start. I picked that up, and made a B-line to the road that leads out of the camp on the right. There is a guard standing in a booth - tranq him. Stand on top of the booth and you have both targets well within your sniping range. Pick them off, and then continue to the road to the right out of the area. Should take you ~2 minutes, and give you an S rank (despite the kills).
Destroy The Anti-Air Replacements I found to be a lot of fun. Take your time, remain unseen, kill no one, and go for the Rescue
achievement, and you will be fine. I highly advise using the C4 for this mission, and remember: you only need to take out 3 of the guns, so focus on the ones that are not overly guarded. A lot of the enemies use the same patrol patterns as in the Ground Zeroes mission, so you should be familiar with what guards are stations where. I had a blast here, and kinda lost track of time, but even using an excessive amount netted me the S rank while saving all 4 POW's.
Just remember: this is a stealth game. If you run-n-gun, then you going to have a bad time
. Remain unseen, kill no one (with Palitz and Glaz being the exceptions
), and (for most) try to make it snappy and you will get the S rank.
Also, as an end note: When I say "Do not abuse
checkpoints", I mean just that. Hitting checkpoints in the double digits is ABUSE, and you will pay for it with the nasty negative points modifyer that hits you endgame. Understaning where the checkpoints are is helpful, but every time you use one it is -300 points to your total score. No reflex (most of the time) will offset that and then some, but if you are hitting those checkpoints like crazy (i.e. ABUSING THE CRAP OUT OF THEM) and you end up with a -3,000+, then it doesn't matter how awesome you were everywhere else: you won't get the S Rank.