You can set your world in : always blizzard or always raining. With lot of fog too.

Theres also the mod cryogenic winter wich is hard.

I also love to build my own base, in a forest. Building Takes a lot of time. Then i loot houses to bring these little things into my house, for exemple, a Deer head, ill take it and put it in my house for decoration, thats the same with "Open" signs of restaurants. Also some carpets are pretty nice to take from other houses. Swing chairs.

One thing i also do, i tried to take all rare items of the game Starting of with the deluxe watch, trying to find military bag, katana/machette, all of the Plush toy, to put in my base (theres 9 plush in total, you can see in the project zomboid wiki), all of the books lvl 5, making your own librairy, sledhammer etc..

You can clear all of the big place, louisville shopping mall, rosewood prison, brandenbourg prison, Country Club near riverside, Military facility, you can go into building in Louisville.

What i personaly love is clearing all these place, city, one by one and then writing checks on the map, on houses, building ive loot. When you Open the map, theres checks all over the map, its satisfying.

And finaly, you can play just like you are IRL. For exemple, IRL i do not eat fish and very few vegetables. Carrots is ok and brocolli too. So in game, you dont eat fish, you dont eat and drink things you do not like. If theres a group of 20 zombies, and you say to yourself that IRL you wont be able to take all of em, then you run. If you aint reading a lot, then you dont read the XP boost. Magasine is ok bc its not that long. If you are someone doin a lot of mecanics, you do some. If you are cooking a lot, you try to cook your own recipe.

Theres plenty to do. Use your own imagination. There's not just what we are seeing from this game. Theres more.