None of them are back. It starts off right where 2 left off and with a different American unit. It's actually a pretty good game. The multiplayer seems very well rounded and fair. Also, the KSRs are selectable if you get all of them, so you can actually
use your UAV while you have an airstrike ready. They put the nuke back in though as a permanent KSR, but it's not a game ender and, as far as I could tell, the points are doubled for kills. LOTS of new guns along with some old faves, but why the MP5 has less
accuracy than the UMP is beyond me. EVERY main weapon has new skins and can now be a golden gun, not just one in each category. I haven't looked at all the maps, but the radar layout for each one is a lot more organized, as anything that has a shortcut or
underground section will be in blue.