Single Player (Campaign)
A-ability for four-person split-screen co-op.
B-enemies adapt to your play style at higher levels. (IE: if you always use a shotgun, enemies start becoming elite CQC specialists.)
C-return of an emotional, dark theme used in COD: WAW.
Multi Player
multi player aspects
D-handguns as the only secondary weapons, organized by type (revolver, pistol, etc.) (maybe also rockets or standalone grenade launchers.) *return of perk: OVERKILL
E-stronger frag grenades, power the same as COD: WAW.
F-grenades used for grenade launchers take up frag or equipment slot.
G-grenade launchers have a slight inaccuracy and unpredictable flight path at farther ranges.
H-different grenade types. (pineapple, lemon, etc., all with different kill radii, blast radii, fuse time and throw distance.)
I-accurate weapon graphs.
J-unique attachments for certain guns. (IE: long bayonet for one gun that increases player weight and a shorter bayonet for another that decreases knife time, but has, obviously, a shorter reach.)
K-realistic bullet ballistics. (bullet drop, bullets curving through walls, etc.)
L-bullets not disappearing after death.
M-realistic recoil of guns.
N-shots fired zoomed-in have a higher damage multiplier to the head than hip-fired shots.
O-a knife only delivers one-hit-kills to chest or head.
P-alternate color schemes for the color-deficient. (like me.)
Q-feedback section or menu, allows players to send complaints or suggestions via in-game text.
R-option to arrange scoreboard by kill-death ratio rather than number of kills.
S-(if killcam and game-winning killcams return) option to save killcams to harddrive before respawn or post-game.)
T-option to automatically skip killcams.
U-ability to copy game to harddrive.
V-unlockable gold (or other “final”) camo available for all guns. (maybe also for grenades or knife.)
W-extra attachments, weapons, perks, etc. available after prestiging.
X-once a prestige weapon/perk/etc. Is unlocked, doesn't require reunlocking on higher prestiges. (IE: if unlocked through prestige, stays with you forever.)
Y-complete customization of button/control map. (IE: ability to switch melee button with down on d-pad.)
Z-playlists that disable killstreaks and (or) perks.
AA-inclusion of night maps.
AB-upon (re)spawning, player has two seconds of invulnerability to explosives, knives, and has a 1/3 reduction of incoming bullet damage.
AC-some weapons or other aspects of the game are unlocked only through completing objectives, like capping a flag on domination a hundred times.
AD-(on Treyarch's side) ability to add weapons, perks, etc. through DLC.
AE-all weapons' damage slightly decreased from MW2.
AF-release of a public beta to iron out the rest of the issues.
AG-classic playlists, back to the basics. (health packs, guns scattered around map, etc.)
AH-all playlists, toggable from third to first-person view and core to hardcore.
AI-inclusion of 3D gun camo. (IE: a sniper rifle's very own ghillie suit.)
AJ-multiplayer achivements and trophies along with single player.
AK-ability to play split-screen with a friend (locally) online. (IE: bring a local “guest” into a lobby.)
AL-a more reasonable 50-60 maximum rank.
AM-ability to search for matches based on map, average rank, average kill-death ratio, country of host, etc.
perk ideas
AN-perk to speed up actions. (IE: capping a flag)
AO-perk to only allow teammates to use your gun after death, and teammates receive a ammunition after walking over your body. (you receive points every time this happens.)
AP-perk to allow prone while on back, can't shoot while in this position. (IE: feign death, but name still appears overhead.)
AQ-perk to allow all enemies spotted (visually) to appear on your radar and appear on anyone's radar that's near you. (countered by any “cold-blooded” perk.)
AR-ability to not choose/deselect a perk.
killstreak ideas
AS-a fixed 3-5-7, but allows selection of each killstreak reward.
Zombies (if included)
AT-larger maps, with up to eight people per map.
AU-four-player split-screen co-op.
AV-ability for two players playing split-screen to pair with others online.
AW-a “boss” zombie, or a slower, more deformed, more powerful end-of-round-type enemy.
