I'm bumping this partially because this thread is so awesome (thanks for the updates to the list BounTyHunteR Zero, as well as everybody else for contributing after the OP.)
I also want to note an error in the chapter listed for a certain medal:
149. Defeated a flying B.O.W. with the snowmobile (Jake 4)
Is actually (Jake 2).
Two more things...
156. Killed 3 enemies armed with gatling guns (Chris 5)
I have some more testing to do with this, but feasibly it could be completed in (Chris 2/Jake 1) during the fight with the two Ogroman. My idea is to use the lower gatling gun to shoot the gunner of the higher gatling gun, then when you get to the higher gatling gun, use it to take care of the two snipers that typically spawn across from it. Ideally a co-op partner should keep the Ogroman occupied so it doesn't punch your gatling gun or throw the instakill van at you.
And yes, the medal description is very misleading according to ahsisi's information.
Something important to note is that
161. Destroyed 5 or more enemies using the turret-mounted cameras (Jake 3)
cannot be completed in single-player. Only one enemy spawns in the balcony area that the camera first looks at and it's not possible to get enemies to spawn in single-player by blowing Sherry's cover. In co-op, the enemy that normally spawns in the following hall patrols that balcony area as well, so the player controlling the camera can get two kills there, and three from the third camera (it's not possible to lead enemies from the locker room into the path of the third camera; they will forget about Sherry and turn back once they pass the door into the computer room.)
Finally, of course, only the person playing as Jake gets the medal. =/
I feel like there were a couple other chapter number mistakes, but it all seems correct according to my memory...Maybe I'm thinking of some medals that could be earned in more
than just the specific chapters listed. Again, though, I can't remember which ones those were.
Originally Posted by darkmikasonfire
Pro Tip: do "Beat the cave area without killing any enemies" on co-op, it is one the most annoying pieces of shit on the planet to do solo, I would know I just did it, took me close to 3 hours. Really pissed me off the amount of time going into it and the amount of deaths, my time and death rate were both D rank simply because it doesn't go lower, however I shall NEVER have to do that medal again so next time, all things will die.
Why was it so difficult for you? Was the AI not initiating the partner action halfway through quickly enough? Also I figure I'll give people the steps for it, just because. It's just three:
All you have to do is follow the first bug until it turns around, run forward, jump off and get into the dumpster.
Once Ustanak has passed, follow the next bug until it turns around, leap off the cliff and push the box immediately: the cutscene triggered by pushing the box all the way ends the current alert.
Then, simply wait for a bug to pass by, sneak through the middle section, this should get you right beside the stairs, then just sprint through the two bugs in your way and head straight to the door.