I've pretty much got all the achievements in the game except for that stupid one where you have to knife an arrow out of the air. I truly don't have the patience for that lol.
One thing that I would like to see in future resident evil games is a merger of the RE1 type of of atmosphere with the gunplay/co-op of RE5 and the item management of RE4 lol
Took me about a minute to do that one. in like, 1-2 right as the chopper comes back, there are guys in the distance with the arrows, whip out the knife and swipe. It's pretty easy.
For me, what's not working out is trying to blow their head off while they're jumping at me.