1)Net security
Like Crysis 1, this game is being plundered by pirates like prostitude's holes.
Talk about cracked servers hmm?
and WORST OF ALL H A X O R S.
I don't care if servers go down for a week or whatever. Get this thing fixed.
I'm not advancing a tiny bit from lvl10. I'll just replay singleplayer constantly. It's still a great fun.

2)Advanced graphics settings(I am in conflict with #1 but I will give this up).

3)DX11 (which will most likey patched along with #2).

4)Graphics glitches(This should be #2 and other go down a rank, but I put this last since when DX11 is patched, different kinds of glitches will form).