I've been playing this game forever, and I started to feel like the tension of the early days is gone. Whatever settings I picked, I had a fairly stacked base in a couple of weeks, and the game changed from being forced to do missions to get stuff I need, to make random missions to get stuff I want. Decorations, sports cars, whatever. And that just wouldn't do.
To tackle it, I created a PZ settings/mod combo that is pretty challenging, relatively realistic, and is ultimately doable (I think), but only just. My goal was to make something that is relentless early on, but also keeps you on your toes much longer than the regular game. I've been testing it for a few days now, it's certainly not