Just copy Pasting my review from Steam:

I have mixed feelings for this game. At 2010, this game was a really good PVP zombie game. However, community started to grow in toxicity day by day, until I forgot ZPS. When a light of hope in the form of achievements arrived to ZPS!. I returned, to find bugged cheevos, that melee weapons have a lot of undesired changes and furthermore, community was full of cheaters and people will serious mental illnesses (A group of harasser tried to stole my account, and followed me to other games, for "fun"). After 200 hours I have no luck with achievements and finally removed the game from my library.

After Covid complications and a brillant magister in my own, I wanted to close all past cycles. And armed with a current group of friends, we decided to give a chance to ZPS! once more. The game have the same aura, win as a survivor is harder than win as a zombie, maps are fun to play with objetives, whilst survival is not fun at all if there is not Cooperation. I completed the game successfully in three different accounts and my friends too. But, we go through too much harasment in all servers, that sometimes forced us to stop our grind, apparently some users have a grudge against Achievement hunters. In other hand, community only know to play Church maps, what is very boring, you cannot progress with that. Maximum count of players at least reach 40 in all servers per week, in other words, is harder to get all achievements ASAP without a group.

A lot of players that still playing are veterans and probably good people, but few of them are permanent harassers, the "little issue" upon which why ZPS have a dead community out of Discord. << Note_ don't care since they can change their Steam nick-name>>:
-Impact- _ a dude with cheats (or mods whatever he says) that cries in its youtube channel when other users end banning him, for the first or because he is annoying.
Azis _ a dude that defines itself as a beta male.
Scorp_ 9k hours player that do not have nothing else to do than harass people.
Sanic the edgedog/Shequelo8/|{sT}| SuperBonker/♥♥♥♥/n word _ another multiaccount harasser.
Pixelo _ a old man that have serious mental illness, harass you through all servers with microphone and pick important progression objects to go afk, while time runs out.
Mr. Kokonut/W0llFy _ without comments (you are good man, but IDK why you have that kind of attitude to us). Hope you get better.

All these players above are gonna follow you in all servers to ruin your fun. All advices from admins and moderators are useless:-"mute them", "block them"- of course this will not work, and sadly, despite we have help from them. Most of those players continue to harass us until we finished the 100 % completion. A group of them avoid the ban easily, so they are always free to do whatever they want. ZPS! needs an urgent permaban option of the "Steam ID", not IP/ nor Url ID ban nor current name, or simpler, Devs can emule some other games tools, for instance, the block option of L4D that prevents harassers to enter the game whilst the victim is playing. They will be forced to pick another server. And if they insist, the only way will be create a lot of steam new accounts, that is tedious progress, in order to harass someone. Most of these low lifes, only play ZPS! and live in the game, so... guess why your game is still dead after 13 years. I never understand, how Moderators are powerless out of its own official servers. Sorry but if the community is still like this, better get away from this Classic, is not worth deal with its current state 4/10 (★★☆☆☆).