Short, but engrossing, Walking Dead is definitely more interactive story than a traditional point-n-click adventure.
It's only about 2 to 3 hours in length, and your actions and dialog choices have some affect in how characters respond to you, and there are a few choices that will have lingering effects in the overall game. Of course, the game isn't going to let you hose your ability to finish -- it's more affecting how the story unfolds. It will match your personality, and game-playing morality, essentially.
In other words, this game is really here to set up the rest of the chapters -- it's not quite an adventure game, but the storytelling is compelling enough that it pulled me in, and may for you as well.
The good:
+ I like the 3d models with pencil-sketch style drawing on top
+ Good audio and music
+ Voice work is generally pretty good -- as usual, kids are a little stiff, and a few performances are corny, but still solid.
+ Good pacing -- just like a movie or TV show, with exciting high points, quiet exploratory segments, etc.
The not-so-good:
+ I had some major game-save bugs that other have had. I had to play through the whole game (again, it's only a couple of hours) in one sitting.
+ Very linear gameplay -- I would've liked a FEW puzzles, even some game-ender choices. I felt like I was being led through an inevitable outcome and my choices were superficial.
Overall, I think it's worth playing if you like adventure games and horror movies.