It's hanky as all hell, but pretty fun. It's in third person perspective and there is a campaign involved with the default option and that campaign is largely forgettable. The other two options are two alternative scenarios, one where you choose a type of character and are dropped somewhere on the map and just survive. The other is more of a shoot-em-up of sorts.
The world is relatively large with a fair amount of variety. There's wide open fields, small town feels, abandoned homes and other survivors trying to do what you're doing. The basic game loop is to start at your main base, figure out what you need (food, lumber, medicine, ammo, etc.) and scout around from a high up area to determine what might be the best way to get that stuff.
Let's say you need food, and you see a gas station. Safe bet that there will be food stores inside. You travel to the gas station, battling zombies using a variety of melee/guns, root around the store and pick up smaller items and larger packs that need to be opened up back at base. Along the way you can discover zombie variants that are super difficult at times. There are also "hordes", which are clumps of zombies that will overwhelm you if you're not prepared. There are multiple ways to deal with zombies. You can deal with them one on one, sneak around them, make some noise to draw them to that location and sneak away, or plow through them with a car and be quick about it.
The game does exist in real time. So if you start a game, be prepared to go at it for awhile. Let's say you start the game, go on vacation, and come back a week later. Game progress will still have happened, along with diminishing resources. That shit sort of sucks.
I can't understate how janky the game is. Textures look pretty alright, but movement can be a little cumbersome and zombies have a habit of being and existing in areas that they shouldn't and suddenly zooming in behind you. It's not a huge issues, but a lot my deaths happened because of dumb physics.
All in all I had a good time with it though. It's enjoyable enough and I love the fact that it's decidedly single player focused. For that price you really can't go wrong.