I'm very impressed, booned. That's the hardest difficulty, right? Because if it is then well done indeed, that game is extremely difficult. I haven't even got that far in the game, and I'm on one of the easier settings. So again, well done.
Brass Balls - Complete the game on Hard difficulty without using a Vita-Chamber - 100G
Seriously Good At This - The player has completed the game on the hardest difficulty setting. - 40G
Got both of these in one playthrough. It took a few nights to finally unlock them but I got there in the end. It wasn't that hard, but it did take a while. Didn't use that much Adam, mainly because the Big Daddies took a lot in the early stages. But once I got more powerful weapons they became more easier.
Also saving a lot helped, plus the Telekinesis Plasmid is brilliant, killed some many enemies with that alone. As usual, Fontaine was a breeze.
Historian - The player has found every audio diary. - 50G
After I did the hard achievements I went back to an earlier save and started to collect all the diaries on the easy setting. Didn't really have that much more to collect, roughly 25 or so. Probably took me under an hour, maybe even less, to get them.
So with those three, I've now unlocked all the achievements for Bioshock - 1100/1100.