Go to replay mission. And go through each one. Each will have stats and I think the highgest difficulty you passed it in. Could be imagining things though. If they all say supersoldier. Make sure you started a new game in supersoldier and passed the submarine part just in case.
If all of the above has already been done.... then not sure man. Most likely a bug?
PS: to answer the other question. No you dont need collectibles to unlock supersoldier
Go to replay mission. And go through each one. Each will have stats and I think the highgest difficulty you passed it in. Could be imagining things though. If they all say supersoldier. Make sure you started a new game in supersoldier and passed the submarine part just in case.
If all of the above has already been done.... then not sure man. Most likely a bug?
PS: to answer the other question. No you dont need collectibles to unlock supersoldier That's exactly what I just told him.
The "intro" level (In At The Deep End) also counts towards the achievement even though viewing the level list doesn't show anything for it. Try playing through it.
Get off your 2 feet tall high horse and build a bridge out of dinosaur fossils with the sweat of your brow only using your shin bone and roofing nails. Then tell me to get some help.