Get all nanomachines within 1 playthrough in Campaign.
This is the only really non cumulative achievement; it must be in one playthrough. This isn’t as hard as it sounds. Most of the nanomachines are bought from vending machines. So what you must do is try and save up as much as possible, whenever you find a vending machine buy all the nanomachines BEFORE purchasing anything else. Only certain ones are found in each chapter. So what might be available in the vending machine in Chapter 2 won’t be available in Chapter 3. If you keep doing this you won’t have a problem. However there are 6 that you must find. (Thanks to DOPE BOI)
After you go swimming and use the zipline to go up, it is very hard to miss and is on the ground on your left.
This one is in Chapter 1, it is after a Iron Whale drops off some enemies, it is in front of a big barricade, this one is very hard to miss. It is right before you meet the scavengers. (Assault: Bulletproof Skin I)
This is in Chapter 2 on some barrels near a vending machine and car, it is right before you fight the grand lancer and jump on its head.
This next one requires 500 credits, after you fight and destroy the Spider robot you will be taken to a underground city. Turn around and walk in the opposite direction of a alley. There will a Yakuza with a tattered Red number 18 jersey. Talk and buy this off him.
After talking to Mifune and you say goodbye to Yuki and before hopping on the Jet skis in the same location, there is a fenced off area. When you walk in look to your right it should be in the corner.
This is in Chapter 2 and is the time when you are by yourself in the Sewage treatment plant, when you are going up to save your team, it will be on the top floor on a table, just look around carefully.
Once you have these, just keep buying Nanomachines from the vending machines and this should pop near the end.