At its heart The Walking Dead is as emotionally affecting an experience as you can have during a video game. Set in the Walking Dead universe of the graphic novels, the episodic adventure series tasks you with getting your group of survivors (most specifically your young ward Clementine) to as much a safe place as possible during the zombie apocalypse. The intensity of the game comes from the difficult choices you must make, choices that seem to transcend the traditional good/bad choices found in most branching video game storylines. These choices provide the backbone for the game's "puzzles" as it chooses to focus on them over the linear object combination puzzles common to adventure games (though it has those as well).
That being said, the multitude of choices doesn't really seem to ultimately affect how the story turns out. While your experience may vary on your way to the ending it seems completely set in stone. This makes for good cinematic flair but for a game so devoted to giving you choice also feels like a bit of a letdown for a game that gives you so much input into how the rest of the story pans out.
Still, the story and characters are fantastic and anyone looking to experience this game should really avoid any spoilers as being put through the emotional wringer is what makes The Walking Dead so memorable.