This is the Dark Souls of FPS games. Harder than Dark Souls actually... Any loot you find is yours to keep or sell, and when you die you loose everything you have equipped. It's pretty hard to describe the nuance of the game in a sentence or two. But here it is as brief as I can make it.
In this game you try to complete quests and find loot to earn rewards and money on your main character, the PMC. You equip your character with whatever gear/loadout you have available and want to risk, and then you start the mission or 'raid'. You are in a game with about 6-12 other players (depending on the map) who are all hostile to you. There are also a number of NPC 'SCAVS' with loot of their own on each map. The goal is to either kill or avoid the other players/NPCs, complete your quest objective, find any loot you can, and extract with all the loot (and your life). If you die you loose everything you were carrying (you can buy insurance for items but it isn't guaranteed you'll get them back, if another player picks up your items it's gone forever). There IS a small 'safe box' that you can put a couple of high value items inside that you will keep even if you die in the mission. This is the saving grace of the game because you can usually find some valuable items (or quest items) that will at least cover the cost of your equipment in case you die.
The game has real world weapons and ballistics, and models real life. The game is 1/2 'gun simulator' in the number of weapons and modifications there are... And there is NO hand holding in this game. There is no minimap, you need to memorize the map. And you can and will die in one shot to the head. You WILL die more often than you successfully extract. Especially in the very beginning. But when you do extract with even a couple items, you earn enough money for a few runs. So you only need to survive like 1/4 of your games. In the very beginning when you are learning the maps, you probably wont even survive that much. But that's OK because........
You can also spawn as one of the 'SCAVs'! This lets you play on the NPC faction (a 'Player SCAV') with a random loadout and weapon without risking your own gear. If you extract as a Player SCAV you still keep everything you had equipped (including the free weapon) and can then use it on your main character. So this keeps you from getting to a point where you've lost everything, all weapons and gear, and all your money, and you cant start a mission as your main character with anything but a pistol or even just a knife... Just do a couple "scav runs" and you'll get a couple weapons and some money to play your main character a few more times.
Now, there will be games where you are running from one spot to another and instantly die and you have no idea where from. Then there are games where you see a guy running from one spot to another and you get him with a clean headshot and drop him instantly. This will also happen when you are looting, and when you find another person looting.
Thus, the only way to get ahead in this game is to play a LOT of games, and just accept the fact that you are going to die. Each game you learn a little bit more and slowly progress your quests.
It's a very fun game with great replayability, but it DOES require some actual effort in learning the maps and game mechanics. Once you do, it's very rewarding.... I don't mind a steep learning curve in a game if the reward for putting in the time to do so is worth it, and in EFT it IS worth it. It gets better and better the more you play, but not everybody will be able to stomach the number of deaths it's going to take before you know a map.