The SP campaign is fine. It's no ARMA, but it's also no COD:MW.
I'm going to put it this way.
It's somewhat realistic.
Graphics and Sound:
*Sound is fine, voices often have a disjointed robotic feel because of how it is handled. Weapon and vehicle sound effects sound fine.
* Graphics wise, the lighting is good, the shadows are good, textures are horrible though. Textures tend to be low rez, though I think it's to compensate for the draw distance which goes up to 35km.
*The devs mentioned trying to go after the WWII black and white photo artistic style, so expect a lot of bloom, sepia tones, etc.
Damage model:
*You can die in 1 hit, you usually don't unless it's a large caliber/high energy round.
*Mounted MG or sniper rifle will kill you in 1 hit, an assault rifle shot to the chest/arms usually does little to you once you stop the bleeding. A 5.56/5.8mm bullet to the legs will make you move much slower.
*Medics can heal squad mates to full health after they get shot, assuming the guy isn't dead.
Ballistics model:
*External ballistics is alright, elevation is accounted for, so is travel time (lead a moving target or you'll just kick up dust), windage is not(always assumes 0 wind speed). There is no spin drift or ballistic coefficent in the calculations. BC is not a big deal unless doing extreme range sniping, but spin drift of a 5.56mm bullet is significant (2.3in per 100m) and I would think would be easy to program for, though for simplified gameply, I can see why they left it out .
*Terminal ballistics is simplified. I have never seen a realistic terminal ballistics model so whatever, not a big deal. It's very, very difficult to program bullet models transitioning through materials. The bullet will go through in a straight path instead of calculating entry and exit angles, again not a big deal, waste of ammo to shoot through walls anyway since you cant see the enemy.
Guns:
*Guns are usually pretty good. A single M82 shot will drop anyone, a single 5.56/5.8 shot usually won't unless you get a head/upper chest/neck shot.
*I find you can usually take more bullets than you would in real life to your body. 2-3 center body mass hits or 2-3 leg hits before being incapacitated is usually a worst case scenario in real life. I've pumped up to 5 bullets into an enemy before they die if you don't aim very well and spread out the rounds.
*Recoil is very good. 5.56 and 5.8mm bullets in the QBZ 95 and M4/M16 doesn't make your aim go insane, there is very little recoil on those weapons because of design and kinetic energy. Both have ~70% the kinetic energy of a 7.62mm Nato round, The M4 had a revolutionary(in the 70s) buffer and stock inline with the barrel to eliminate barrel rise, the QBZ 95 is a bullpup configuration so it's naturally inline barrel and stock and it contains a fairly complicated and effective recoil mechanism. A heavier weapon like the M82 or M40 will have much more recoil.
*Scopes on assault rifles work well. Scopes on sniper rifles are not adjustable in game. *Overall sniper missions tend to be more run and gun than true sniping (imagine more like Ghost recon, less like real life) for gameplay balance and pacing I guess.
*All scopes from the CCO to the SSDS are zeroed at 100m , remember that when shooting. I never use iron sights because of my play style so no idea what they're zeroed in at, but 100m would be a good guess.
AI:
*Nobody can shoot for crap, though I have the feeling most of the AI tends to just go for suppressive fire. Beyond 200m, don't worry too much about incoming fire if you're behind some sort of cover. Heavy amounts of fire inside 200m and moderate fire within 100m will be quickly cut down you and your fire team though.
*It's like the Chinese shoot like Iraqis. I'm not actually sure how well/under trained Chinese troops in real life are but they're not very accurate in this game. I get ~40-45% hit rate, they have low single digit % at the ranges I engage at, which is usually Designated marksman range (minimum 200 meters, usually 300-400).
*Your own fire team usually isn't too accurate either, but they're a little better even though you almost always have at least 2 guys with iron sights (fire and assist positions in the marine corps fire team doctrine, well assist is actually a corpsman instead of a true assistant automatic rifleman)
*Enemy AI will act decently intelligently, though I wouldn't consider them all that smart. Sometimes they will flank you, sometimes they will just suppressive fire you if they outnumber you (which they usually do). You can give them the slip and find them flanking to your last known location only to stand around confused as to where yo went, which is nice (no 2km see through trees and cover supermen here, line of sight is usually pretty good).
*Sometimes, they won't react at all though. I've shot at enemies as close at 300m away only to have them go prone and lie there facing the wrong direction (M16, non suppressed rifle). Very rare though, I think i remember this happening once or twice.
*Overall I think enemy awareness is alright, except at night, it's like nobody in China has NVGs, which make night missions much, much easier. Again, this harkens back to the previous US conflicts. Yes in Somalia or Iraq, US troops had a massive advantage in night operations, but I would expect China to be much better equipped/trained than those 3rd/4th world nations.
Interface:
*Giving commands means you have to stop moving and use a radial menu. Pretty annoying (and deadly in a firefight)
*You can't look around while driving. Also sort of annoying and reduces situational awareness.
*You can play with a normal interface (ammo left, compass, target locations, waypoints, etc) all the way down to hardcore difficulty (no HUD at all). Difficulty levels do not change AI awareness or accuracy.
Gameplay:
*It's fine I like it actually. It's a "friendlier" ARMA/OFP1. It's not a punishing as those 2 while not being as arcadey as the mainstream shooters.
*Biggest thing to remember, it's still somewhat unforgiving. You can do everything right and still fail a mission/take a stray round to the head through luck of the draw. It doesn't happen too often, but it can be frustrating sometimes.
*I usually never use vehicles, so I can't comment on it too much. I feel like it's way too easy to die from 1 stray RPG round and makes you a much bigger target so I almost always hoof it. The game is relatively forgiving since you can accomplish objectives in either vehicles or on foot.
*On normal difficulty, checkpoints heal you and heal/resurrect any of your squadmates. Makes the game a bit easier, but less realistic than Hardcore with no saves, no checkpoints and no healing/resurrections.
*Watch the position of any friendlies on missions with them, advance with friendly support or it's 100% suicide, most of my deaths come from poor awareness of where friendly forces are and advancing too quickly.
Overall, it's a game between genres. ARMA/OFP fans will cry found because of the dumbing down while COD/Halo fans will be pissed it's so much more difficult. Either way I personally think it strikes a good balance between difficulty and fun and I really enjoyed the Single player campaign. If you enjoyed Ghost Recon, you'll probably enjoy this game and for $40 I think it's a great buy if you like this sort of game.