It's an amazing zombie survival game, it's extremely challenging but that's just part of the fun. It's supposed to be that way, you can't fight endless waves of undead because you will get tired very quickly and then you will unable to run from them, barely walking until they catch you. Or you will get sleepy and your attacks will do less damage.

You need food, to get it you need weapons to go trough the undead, to get the weapons you have to scavenge, to scavenge to need backpacks and when you have that you need a car.

For me the fun in Project Zomboid is about gathering all the tools that you need to survive and even thrive, but once you get all that there isn't much to do. At least in vainilla, but you can add mods to spice things ups or even better play with your friends.

I've invested a few hundred hours in this game, and i love it. I barely have been able to survive two months, because every decision can mean life or death. One mistake is all it takes to get bitten by a zombie you didin't saw or heard, or your car dies on you in the middle of a hoard and that's it.