Interesting, janky, cheap, pretty fun...
As I said earlier, I'm a big fan of survival games. Be it retail releases like Silent Hill one or two, games like Don't Starve, which I picked up for $7 (I think) while it was still in beta, or those like DayZ (just got back into it), which, although a free mod, cost me $20 to buy Arma II and Operation Arrowhead. That being said, SOD comes in about where my expectations were laid.
Now, for the game itself. First off, I'd like to say that I really like the soundtrack that this game offers. Perhaps it's a bit limited, but being someone who often turns the BGM off in a lot of games, I've enjoyed it so far. To this point, I've put about 12 hours into the game, and though some of the missions have started to get repetitive (especially the ones where place x is besieged, as I usually have two or three of the same damned mission at the same place within half an hour of each other). Other than that, there's a pretty good divergence with mission parameters. The weapon selection is fairly diverse, ranging from tree branches to assault weapons, all of which have durability and can break. One of the complaints I have on this aspect is that I would really like to have a first-person view when using sniper rifles and scoped assault rifles.
The character design isn't bad, although at times certain people act in a manner that doesn't seem to match with the personality that has been established through earlier parts of the game. There is also quite a bit a jank involved here. Zombies glitch through walls, cars crash at random points and generally handle very poorly, and I've had some cut-scenes and dialogue cut out in the middle. Most of the time, it doesn't impact gameplay significantly. Frankly, it's cause me to laugh pretty damn hard, to be honest (i.e. good indie jank...), but there have been a couple times, mainly when story dialogue was skipped, that pissed me off a bit. Also, the lack of any manual saving is fairly annoying. Being someone who is used to survival games, it's not a huge issue, but still, it would really be nice to have a quick save or at least one hard save, especially because it's possible for someone in your group to die because you missed the announcement of a mission they went on.
Overall, this game definitely has it's problems, but at $20, it's well worth a look. It's not the hardcore, 'realistic' zombie sim of DayZ, nor is it CoD's zombie horde. It fits somewhere in between. It could definitely be improved, and hopefully will be. Either way, I've so far enjoyed the game, and will probably dump another dozen hours into it.