Nether started out great and I was a firm supporter of it when it was released on steam from the get-go. I put 281 hours into it according to steam.
Basically in a nutshell, think warz(iss). Open-world map, you spawn on the map with a knife and need to find locations that spawn loot in order to survive. It is an mmo with a server browser and you run into people frequently on higher pop servers and its basically a free for all. Any player you see you can kill and take everything on their character, and viseversa.
This is not a zombie game, instead you fight monsters that spawn around the world that can teleport, which can be overly-annoying due to the fact that every single monster other than 1 type teleports everywhere. So even if you shoot the monster that is basically 3 feet in front of you, it will teleport. I believe they have done this because they do not know how to code adequate A.I pathing, thus they made the monsters constantly teleport in order to make up for bad pathing. The trade-off of this is that the game becomes overly-annoying after a while.
There are a number of different monster types that have different abilities, some spit on you and scream attracting more numbers while others simply try to melee you. They do not use weapons, think mindless beast monsters.
The main reason I am giving it a low score is because the developers do not seem to have any actual direction that they want to take the game in. This game is all about PVP when it started, its a K-O-S (kill on sight) based game in terms of player interaction with other players, because you cannot change a kill-on-sight (pvp) concept without hurting the entire game you have developed from the ground-up to be literally structured on that concept, then try to change it with different mechanics. An example of such a mechanic that they added in a patch would be a blood meter where you gain a blood point every time you kill a player, and when you kill more players in a short amount of time you get more blood points and each point increases your agro radius for the nether (monsters). It's just really bad game design and doesn't even stop KoS in the slightest, it just makes the game more annoying to play. Also the weapons are a bit dull over all. Very limited selection and no way to customize it.
They added crafting weapons but then nerfed weapon spawns severely, which made the game 10x worse.
There is cosmetic customization and a skill tree. Basically the skill tree is one of the worst I've seen in a very long time and makes the game completely imbalanced on top of the fact that if you die you it resets your skill tree.
Honestly I don't have a problem with the skill tree being wiped when you die, my main issue with it is that it breaks the game. A short example for this, the level cap is 31, and you gain experience by killing monsters. The 31 cap limits your choices extremely, but everyone gets the exact same paths anyway because certain paths in this skill tree are completely useless and that is a huge problem in terms of game design and functionality. There is no deciding if you want to alter your playstyle the next time you spawn because certain paths are simply too good to ignore while others are abysmal.
Sniping is a joke in this game due to the skill tree, you can shoot a player directly in the head and they will not die. The gun skill tree has "critical strikes" which makes competitive play imbalanced because whoever gets luckier in a gun fight will win based on crit hits if both players are of a higher level. It's just terrible when it comes down to it.
It was good when it first came out, but they are ruining it with patch after patch.I cannot recommend it because the developers simply have no idea who to listen to and clearly have no personal directions that they want to take the game in.