Demonic Spiders: The walkers are absolutely relentless and will often kill you before you even realize what is going on. They move slow and only use melee attacks, but hurt you pretty bad with each hit, often come in large herds, like to play dead until you walk past them and, above all else, are attracted by noise. In other words firearms are near useless and can actually make a bad situation worse and melee weapons are only effective against small groups. Your best chance of surviving most encounters is either using stealth or running away as soon as a big group appears. Anything else will just get you killed nine times out of ten.
Player Punch: Like in the TV show, don't get too attached to someone as they are likely disappear just as you are starting to care for them.
Porting Disaster: Not as bad as some (i.e. Resident Evil 4, Dark Souls), but clearly minimum effort was taken in adapting the game for PC. For starters, it doesn't even have true mouse aim; the game just emulates a gamepad and maps the mouse to it, resulting in extremely jerky movement.
Scrappy Mechanic: While ambitious and looking good on paper, many of the game's advertised features end up being this due to poor implementation. Despite different routes having differing chances of finding loot, you can very often waste a lot of gas taking the longest route and not encounter any chances to loot at all. Also, the survivors tend to be next to useless. Even though you can send them out to scrounge for supplies, they'll often return with critically low health with barely any items to show for it. You usually end up wasting more resources healing them back up.
So Okay, It's Average: To the reviews that didn't outright hate it. They admit it had potential and liked the idea of the management system such as having to ration gas and food and how to proceed to the next destination which give alternate routes. However the lack of threat the zombies pose removes virtually any tension and in the end the game is just another run of the mill shooter.
Not only that but Herd Mode is a joke as the map is tiny and there isn't enough variety. We also have the short campaign and the lack of co-op or multiplayer. Hopefully they'll try and improve the sequel if there is one.
Tough Act to Follow: After the acclaim of the TellTales Games version. This game coming right on the heels of it made fans wary.