EDIT: I had posted my earlier content while frustrated and angry after trying to experience multiplayer with my friends and family. I wanted to articulate my thoughts without those feelings, so I will try again.
After getting to know the game, I started checking out mods, and thinking about things in the game that made no sense to me. I could not enjoy the game at this point knowing what I had concluded to be major problems or missing features. I stopped all of us from playing until I could mod it, including making my own mods. And since I had no experience modding this game, I had to reverse engineer established mods first before making my own, which took about 2-3 weeks before I could start making multiple mods and changes with no errors, and were balanced within the game. This also included making my own custom map and using the world editor, along with third party software to make it more realistic. The offered default maps are a horrible example of what this game could actually be.
This all took me about 2 1/2 months of research, time, trial and error, and hunting down mistakes. And what got me the most frustrated and angry was the fact that after 10 years, this game has very little info or help to make mods or use the editors that is easy to find or access. On YouTube, most of the vids cover the same crap, and none of them are very detailed. Those creators could not even answer some of the more basic world editor questions. Now there are sources for info, do not get me wrong, but when you are looking for detailed or advanced info, it is very hard to find. I have had some luck on a Discord I was pointed to, but the process of gaining a lot of knowledge to modify this game is a long frustrating road. And some of the changes I needed to make before enjoying the game again, I think should have been addressed long ago, so I would not have to use my own time working on it instead of playing it with my friends and family.
Another thing that was really frustrating was trying to add finished community mods to the game. Almost all of them had to be customized as they were completely unbalanced, included features that made vanilla features useless, mixed quality content with crap content, had errors, were not really finished, were not thought out, ruined the survival aspect, etc... One vehicle mod was missing sounds, some vehicles drove like crap, some had the avatar in the wrong place etc... More work for me again.
1. Nothing is more frustrating than watching your nephew just climb up to a tier 5 POI roof, grab all the best loot and come back down. But wait, I thought this was a semi hard core survival game? Food is scarce, you start on foot, what is this? "Don't Cheeze", is a poor excuse for bad design. I know TFP have purposely patched out exploits in the past, so why not this? They could have easily just taken the 50 or so tier 4s and 5s, removed the main loot from the roof, broken it up, and scattered it in 3-5 areas of each POI depending on size. This would at the least make players search or fight through the POI to grab all the loot. Even better if possible, make the loot respawn randomly around a POI. Something similar to this or better should have been a priority. I had to do this myself, and it works great.
2. The skill system. Who at FTP thought is was good to have only 5 crafting levels and immediately be able to craft stone, iron, steel, etc, at the same level that you have reached once the item was unlocked? This takes a "semi hard core survival game" and turns it into a basic, easy mode crafting game. You are telling me that once I am at level 5, get lucky and find the right schematic, I can now craft end game items at tier 5 within 30-60 days or even sooner? You also can skip an entire crafting element like iron tools if you get lucky enough for example. The real problem here is single player vs. multiplayer. Since skill costs do not change from SP to MP, now all your team has to do is min-max diff skills your team needs, making the skill system a joke. My job was to build vehicles. Needless to say I was making the 4x4 in a few weeks of game time. Not very fun, not challenging at all. In single player, your skill choices matter much more as you advance much slower as you have to cover the entire skill system yourself, but multiplayer completely destroys this.
The next patch will address this, but after 10 years, and the latest horrible system that should have never been part of the game in the first place. You should never be able to make iron tools if you can't at least make tier 3-5 stone tools.
3. The game feels kind of empty and lonely. Not many zombies around outside of POI's. No civilians or survivors running from zombies. One type of car to litter the world. No roaming zombies in a POI that you have entered, you need to wake them all up, but can shoot most of them first. Where is everyone? Screamers and hordes are not much of a challenge. And I was told that the POI spawns do not change with MP? This can not be correct. I get the same amount of spawns in a POI no matter SP or MP? Please tell me this is not the case. I had to combine and customize mods to make an occasional civilian/survivor either running from or fighting zombies to liven up the world. I did the same to add a half dozen different vehicles that could spawn along with the default cars, giving more variety and life to the world. I changed the skill system and spread it out to make more sense, while adding more content to fill it out better.
Why has FTP not put more effort into optimizing this game? They said because it is not finished, but 10 years and probably 5+ to go, this game and its players need more effort to optimize this as we go, not 5 more years from now, or even longer?
Why can't we zoom out to see more of the world map?
Why can't we share our explored parts of the map with the team in MP?
Why can't we craft a lower tier of an item if we don't have the parts to make a higher tier, or just don't need the higher tier item?
Why is it taking 12-24 months to get an update that should only take half as long?
Why can't I change the terrain in world editor mode and save it?
Why are most POI zombies set to active instead of attack, making them too vulnerable?
Why has it taken so long to fix water in the world?
Many other questions I forgot.
I actually like the idea of the game, and I see it has come a long ways from where it started. But I still get frustrated at how far it is from the potential it has.