I've played the story twice in this game, and twice the ending moved me to tears; it helps if you played the first two.
In a regular FPS game, you simply get to run around, and just like good old master chief, you can run into a room or field or space ship and take out everybody all by your lonesome by shooting everywhere and jumping around and tossing grenades and taking a hundred bullets as long as your shield recharges, etc., etc., you pretty much win the whole war by yourself; not in Brothers in Arms.
Brothers in Arms: Hell's Highway demands that you take a moment to analyze the battlefield, spot good cover before you advance, and order your troops into position to suppress the enemy and allow you to flank their positions. Your ammo and grenades are limited, but you generally get enough to complete each objective.
The game is part of a series of very well made games based on true events that took place during WWII. The troops that follow you into combat have different personalities and will yell out different things depending on the combat situation. Their interaction with Matt Baker is the core of the story, along with a certain gun.
I must say the cut scenes and on-going story in this game is of very high quality and on its own very entertaining. The cut scenes in Hell's Highway actually reminded me of LOST, in fact the first chapter is called LOST; and just like LOST the whole game leaves you wanting more.
Depending on the mission you get to bring a combination of 4 different types of teams, each with their own unique abilities; an assault team, a machine gun team, a fire base team, and my favorite, a bazooka team. One of my favorite early moments in the game is when we were pinned down by an elevated MG42 position in a church tower, I could've attempted to snipe the baddies myself, but under fire I was able to signal my bazooka team to demolish the tower from a few hundred yards away, it was awesome. Brothers in Arms may very well be my favorite WWII game.
The combat and gameplay are very intelligent and so are my troops. However, you can screw up and get your guys killed. This game is most satisfying when all your teams survive each mission. There is an "authentic" mode where you get no HUD and a couple of bullets will drop you, this is the best way to play. You have to complete the game in the highest difficulty first in order to unlock this.
As of June 2010 there is still an active online multiplayer community, so yes, there is a multiplayer aspect to this game. I own several versions of this game in PS3, 360, and PC and was able to verify ongoing multiplayer in all three platforms, especially PS3.
Don't miss out on some of the best WWII combat you've never played before. This is a Gearbox game, of Borderlands fame.