Nation Red achievements

Perform 20 remote grenade detonations

In an On-line Coop game, upgrade a sentry gun to a weapon station

Kill 3 grenade bosses in one barricade game within the first 20 waves

Pick up Friendly Fire and use a Zombie Bomber's explosion to kill two more nearby bombers

Reach wave 2 in warehouse barricade without any zombie breaching the fence perimeter

Finish off a boss zombie with the crowbar

Collect 10 zombie-attracting Rammers in one game

Complete all the story missions

Get hurt by and survive 10 Zombie Bomber explosions in one game

Kill 10,000 zombies

Reach Wave 8 in Bridge Barricade mode

Kill two Minigun zombie bosses within two minutes of each other