I've been putting in some time into the new online FPS Enlisted. World War 2, somewhat realistic, and quite fun even if it is still in beta. It is, however, a massive grind. After over 10 hours, I just got to my first semi-automatic. In one campaign, on one side. You have to grind up levels for each campaign and on both allied and axis sides.
Or you can buy levels and special weapons. Thus you have whales running around with M1 Garands and Thompsons, while schlebs run around with 1903 Springfields and M3s. Thing is, the balance is good enough that it doesn't really matter. I'm not I'm pretty terrible at shooters, yet I can still bring down whales with even vastly better weapons like the BARs and StG44. For nearly everything, it's one shot = kill, unless you hit a limb. Even SMGS don't take a lot to bring down an enemy, so buying higher tier weapons only gives some advantage, but not so much that it's impossible to compete and have fun.
The downside is that vehicle combat... sucks. The view is first person only, so when playing with a tank, you're looking down the barrel. The tanks get stuck constantly, and are highly vulnerable. I've found giving my tankers SMGs and abandoning the tank is far more effective than using the tank. Planes are worse. While realism is a fine thing to shoot for in many ways, the rule of fun should always take precedence in a game. As of right now, vehicles are not fun to use. The most annoying is that the squad system (more later) requires you to waste a squad slot on a vehicle. I'd rather toss my unused engineers in that slot. There are also an array of trucks and jeeps and kubelwagens around that you can hop in and drive. They're mostly for speedy access to the front, as they are unarmed and armored, and basically make you into a large target.
Infantry is class-based, with the usual suspects, except there is no medic. Instead, everyone in your squads gets a first aid kit. In case you get hit and are not killed instantly, you can bandage yourself and return to the fight. Engineers can build fortifications, ammo dumps, and other neat stuff, and are welcome on any battlefield. Riflemen have perks to give them advantages when shooting things, Snipers er... snipe. Assaulters use SMGs and harass women, Tankers suck until you give them a real weapon, and pilots die.
As to the squads, you actually spawn with a team of AI (missing the I mostly) buddies. Each squad is named for a historical unit, with each member having a name, and the individuals and the squad each gaining levels. In battle, you control one, and the others stand around soaking up bullets so you don't have to, and provide extra ammo for you when they die. Yeah, they aren't smart. They do act as a "lives" counter. Assuming they aren't wiped out before you, getting killed just sends you into controlling one of your squadmates. Whats more, deaths are only counted once the entire unit is wiped out. F2P players get 4 squads, with one forcibly locked into a vehicle squad (tank, plane).
The grind is, as mentioned, atrocious. First you have a campaign level, for each campaign, for each side (axis/allies). This unlocks weapons, troop classes, and vehicles. Then you have a squad/unit level. Then you have a system of upgrading the squads as a whole, with extra troops, higher level troops, and more. Then each person in the squad has their own level, which unlocks perks.
Then there's the logistics system. You have to get orders to buy new troops and weapons. Troops don't come with weapons. Want to add those two new riflemen you just bought? Better buy a couple MAS '36's for them. Otherwise they'll be wandering around with just a knife. Whats more is the silver weapon orders drop only rarely, as do the silver troop orders. Bronze weapon order are just used for random deliveries, and bronze troop orders aren't used period.
The TL
R is that it's pretty fun, but the grind is horrible, and honestly if the basic gameplay wasn't such a blast, it wouldn't be worth playing due to that grind. As it is, it'll probably become unbearable once the devs start giving out broken weapons or perks for whales, but until then, it's a really fun shooter.