Yeah I found that yesterday, easily the best bone charm I've found, really fast choking fun to be had.
On the last mission now and clocked 13 hours. I can see this one lasting 2 or 3 more hours so not a bad game length really. Was considering a replay to find every item on each mission but I just can't see me finding all the money. Last mission I spent ages scouring everywhere and was well short of the total.
Think I'll go for a Ghost run next. That is going to be hardcore challenge though, looking back at some areas I've had to traverse it seems almost impossible.
Anyway, what a superb game.