I feel like designing a CoD knock-off. Here's what I've got so far:
Storyline (I've never played an FPS campaign, so forgive me if I'm directly ripping from one):
The campaign takes place between 1989-2040, however most of the campaign takes place after 2020. Before then, it is a few middle-east missions. However, towards the end of this part of the campaign (2015-2020) much of the US begins to hate the involvement in the area, and you returning to America brings hatred (like Vietnam). In the early 2020s, the newly elected president is killed. The country plunges into general anarchy, like an unofficial civil war. By this time, you have become a fairly high rank among the military. Most of the country expects that political extremists killed the president, but you discover the new president (then the vice president) planned the killing. Although, before you can release this information, you are knocked unconscious, and wake up days later in a small African village. Knowing who is responsible, you become very anti-American. However, you wonder why they decided to leave you not only alive, but in Africa, and not in a military prison, or in the Middle-East where (you're still wearing an Army uniform) would most likely be killed. As these thoughts run through your head, a ground invasion begins. You are literally handed a gun by a local, and left. There is an organised militia formed, but you are still alone. (I've kind of run out of ideas after this).
I think the next few years will be basically American Military Establishment taking land as the militias gain strength. Countries in the middle-east and north Africa join your forces. I think a cool scene would be an expected terrorist you nearly killed years ago, is left alone in a room with you. After this I need to think of the last 10-15 years of the campaign
Weapons:
SMGs
PP-19 (full-auto)
UMP-45 (full-auto)
Vector-24 (some future variant) (3-round burst)
MP7 (full-auto)
AS-VAL (full-auto)
Vepr (full-auto)
P90 (full-auto)
Assault Rifles
SCAR-L (full-auto)
G36C (full-auto)
FAMAS (3-round burst)
M4A1 (full-auto)
HAMR (5-round burst) This will be a heavier weapon with a lot of recoil, but one accurate burst will always kill
F2000 (full-auto)
SCAR-H (full auto)
FAD (full-auto)
ACR (full-auto)
ACE-52 (full-auto)
Shotguns
Spas (10 pellets)
M1216 (8 pellets)
KSG (9 pellets)
AA-20 (6 pellets)
Saiga 12 (8 pellets)
Remington 870 (9 pellets)
LMGs
LSAT
M240B
M249
M60E4
Type 88
AUG HABR
Machine Pistols (are primaries!)
G20
B23R (ah, the infamous op pistols...)
Kap-40
CBJ-MS
JS2
PDW-R
MP9
Skorpion21
Snipers
AMR-2
MSR
M82A3
M40A5
USR
L115
Ballista
---SECONDARIES---
Pistols (faster switch time)
FN 57
M9A1
MP443
P226
Revolvers and other high-power pistols (better hip fire, obviously more powerful, longer reloads)
.44 Magnum
MP412
USP .45
M1911