As an older gamer whose first taste of multiplayer FPS was Team Fortress and enjoyed the Battlefield franchise up to BF4 (playing competitive Desert Combat with a large Australian clan), Hell Let Loose is one of the few more recent games which scratches that WWII team-play itch.
Reliant on comms and teamwork for success, HLL is a game where skilled players focused on god-like KDR can still shine, while those whose best reflexes might be a few years behind them (ahem) will find aspects of tactics and leadership to enjoy.
Well-populated 100-player (50 per side) servers and active clans provide opportunities to play competitively while casual gamers will enjoy the intense battlefield experience reminiscent of hardcore Battlefield. Hardcore, because there are no enemy icons on maps or HUD indicators (other than those shown by flares from recon teams and recon planes from Command, or the direction of a bullet which wounded you), the game requires patience and observation, defence and coordinated offence.
Squads are formed to join the game and successful squads are those with good communication and leadership (there is VOIP which is perhaps the game's most important tool). Playing as commander requires patience and quick thinking (you still get to shoot people), and good commanders are gold.
The classes range from simple riflemen with a rifle and spare ammo (the squad can be made up of just those - the other classes are limited to one per squad), to Assault with automatic weapons and, if you level it up, a butt-tonne of grenades, Automatic Rifleman, Medic, Support, Machine-Gunner, Anti-Tank and Engineer. Each has its unique attributes and weapons and each can be levelled to become more effective.
If you want to be a sniper, it's not so simple. The Recon teams are limited to one Spotter, who creates the 2-person squad and is leader, and a Sniper with a scoped high-power rifle (semi-auto FG42 for level 3 Germans). There are only two recon squads per team and from previous experience, I think the system works well. No more teams made up of 50% snipers who shoot across the map at each other rather than trying to achieve objectives. Instead recon teams are designed to work behind enemy lines to take out garrisons to disrupt defence or quieten artillery fire.
The weapons are typical WWII fare true to each nation (Germans, US, British and Russians) as are the armour available for three-person Armor squads - driver (who drives using a manual gearbox), gunner with AP or HE shells, and a spotter/commander who has 360 degree vision. It's a very different experience from any other tank game I've played, but rewarding if you play it right.
There is so much more about this game which I also enjoy - the spawning system using garrisons for the whole team or OPs put down by squad leaders for the squad; the customisation of each soldier; the well-designed maps; the sound effects which help identify an enemy's position; etc.
But the thing I enjoy the most is the teamwork required to make it work. When it does work with good communication and strategy, it's a very rewarding experience and can lead to some fantastic battles. However, when there is no communication and coordination, HLL can be very frustrating and those looking for a Call of Duty experience won't find it here. The map duration can be long if two good sides are going at it and the learning curve is a little steep, but in my experience there are plenty of veterans prepared to help out if you're prepared to communicate and learn.
Overall, in my opinion, HLL is the best WWII FPS on the market today and will satisfy those yearning for the good old Battlefield days when teamwork made the dream work.

I love PTSD simulator

This is a PTSD simulator that makes you wish AA still stood for anti-aircraft instead of alcoholics anonymous