Having played more of Project Zomboid, I've discovered it really is a lot like other survival type sandbox games I've enjoyed, in that there are a lot of very complex mechanics that you just kind of need to figure out by failing repeatedly.
I had no idea that weight/encumbrance was affected by containers. I can carry more shit by stowing it in a backpack etc, but it adds to the time needed to take it out when using it. First Aid includes mechanics for disinfecting wounds/bandages, which staves off the disease longer if (when) you get bitten.
Also, I had no idea Tyrone Watermelon was born with the ability to hotwire cars, so I could have tried driving during last night's stream, if I'd realized. Once I figured out all these mechanics through experience, it really added to the replayability and fun of repeated runs. I managed to get two days with a good supply of food, medicine, and weapons before I succumbed to the Zomboid disease while fighting off a horde in the middle of a NASCAR track.
Bottom line, it's a pretty solid survival sandbox game.