ttsutaoka

Thank you! Once you get the hang of it, it's not that difficult. Persistence and a lot of swearing is all it takes. Oh, and a fair amount of skill, but that's easy enough.

Yeah, that would be a good bet. :P

That's weird, when you complete the storyline, you should receive all storyline related achievements + the difficulty achievement you started on.
Are you sure you fully completed the game? aka you're in mercenary mode now.