Don't look now, but they finally updated Nation Red. There's something resembling ambition in it (player class system introduced):
Updates to Nation Red have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:
Introducing new player class system with 4 new types: Special Weapons, Gunner, Medic and Scout. Use the Player Profiles to select your class.
-New interface, including the option to disable the video background
-New bronze, silver and gold star based mission rating system
Bomb Threat: All explosions (including enemy detonations) are 25 percent more powerful
Living The Moment:During Bullet Time, get 25 percent faster reload speed and 25 percent more XP
Apparition: Doubles the chance of a ghost powerup appearing
Strike Team: Combines with the ghost pickup to equip them with AA-12 automatic shotguns (Requires Fire Team)
Heavy Sentries: Increases damage done by sentry guns and NPC soldiers by 25 percent
Mercenary: Extends combo streak by 50 percent for increased XP
Gunslinger: Complete any mission on 3 silver-star level using only the default Glock
2x9mm: In one game kill 2 bosses using the Dual Glocks
Walker: Complete the Walker mission on any silver or gold star level
DOA: Enable DOA mode in Free Play and kill 50 zombies during one DOA ghost pickup
Incendiary: Sets any zombie target on fire when shot
New .50 Cal Sniper Rifle weapon
New 3D positional sound option
7 Perk slots are available to pick instead of previous 5
Perks can be picked from list by hitting 1-7 number keys
Several bug fixes and additions
BTW, the very last mission is the "protect the AI soldier" mission. Not really an escort mission -- he stays in one place (he won't follow you - maybe this is when someone tells me there's a way to make him follow you?), and so far I've found it completely impossible to complete it, regardless of difficulty slider mission.
I have some dumb fun with the game, and I convinced a bud (Denmark guy I've done some fun Alien Breed 1/2/3 co-op with) to pick it up. It's fun in co-op but repetitive. I'd have preferred actual maps with the same gameplay mechanics, rather than a bunch of "arenas" that are all pretty much the same. The other modes add a bit of variety, though the absence of anyone ever playing online (even after this fairly major update) makes co-op tough to find.