Buggy controls. I really have yet to find ANYTHING buggy about the controls. If I had to guess, you are probably running on a bad computer and lagging as well.
I’m running it on a dual processor (2×2Ghz) machine with 2gb of ram and it’s jerky for me. I’ll press fire and nothing will happen. It will keep firing long after I let go of the fire button. That is a critical flaw in a shooting game.
I also dislike the lack of health bar. I can appreciate the “blood spattered screen” effect instead of a health bar, but it’s a bad choice from a UI standpoint imo.