It's probably a bit too late for my vote, but try to make the airball fields look a bit more realistic. I know in DPB, it was like playing on a field with wooden bunkers that were painted like air bunkers. If the engine allows it, make the thing shake a little when it's impacted with either a player or a paintball. A long time FPS fan, I've noticed that camera shake and weapon sway are the two big factors in making a FPS captivating. When your foot hits the ground when you run, your head does not stay in the same spot. It's going to move up and down a bit. When you're sprinting, you can't hold your marker up at perfect stance. Most players drop their marker altogether and book it. For more examples of camera movement, compare Counter-Strike 1.6 to Battlefield 2142. You'll see what I mean.