Sound design
I've played quite a bit of this game and I like it but there is one thing bothering me - the sound design. The gun sounds are pretty bad. I often go play something like Hell let loose instead, even though the gameplay is not as much fun (80% of the time you just run around the map) at least you get the feeling of shooting a real gun when you finally get in an engagement. The guns in ER2 sound like guns from a WW2 movie filmed in 1970. I wish the developers would look into it, sound design is often overlooked but does wonders for the immersion.