This game is by far the most complex story game to date. From my point of view, this game stands out against Heavy Rain, Beyond Two Souls and Until Dawn. The Walking Dead is an epitome of a true "Butterfly effect" game.
Those other three games are good, but their story-lines are not as complex as the Walking Dead. In the Walking Dead; You get to choose something and you're gonna see it grow through out the series. Those three other games aren't that close, Yes, different choices - get you to different branches of the plot but for the other three games - it ends there, and the bad part is that their story-lines have an unchangeable plot regardless of your decision. Unlike in the Walking Dead, a different branch not just shows a different outcome but also a different plot point of the story, It's like by your decisions, YOU'RE VIRTUALLY CREATING THE PLOT OF THE STORY! and that is something that makes this a true "Butterfly effect" game.
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To tell you more:
I get to experience the game's complexity by having regrets/random thoughts to some decisions in game. In those other three games, when you lose this guy or gal, it doesn't matter, we're just not going to see them in the end. But here in the Walking Dead, your decision affects the entire plot, especially when you get to save some character against another, you get to think that "I wonder what happens in the next episodes if I choose him/her." Also you get to think, if he or she died in the past episode, what will happen in this episode where if he/she was alive she would still be bitten? Another one is that, if he/she died in the past episode, who will be the protagonist in this episode? with those thoughts in mind; it truly makes the gamer the writer of the story which then would mean that if you play this game; YOU ARE VIRTUALLY CREATING THE PLOT OF THE STORY!