You might end up with two or three different end states, with some minor variations in the mechanics of how to get from point A to point B, but your character’s interactions would have little lasting impact in terms of the dynamics of character relationships. Those games generally featured a lot of puzzles, and while they had strong central narratives you had relatively little control over it. No surprise there, really: several members of the company came there by way of Lucasarts, famous for its adventure games such as The Day of the Tentacle, Sam and Max Hit the Road, and the Secret of Monkey Island series among others. At the outset, Telltales Games made very traditional adventure games.
But the real boom of success that The Walking Dead brought-a success that has led to their Fables: A Wolf Among Us game based on Bill Willingham’s comic book series, and more recently Tales of the Borderland based on the popular FPS-was also paired with a very different approach to the adventure game. These were much more traditional adventure games, and were solid-to-pretty good. I myself have had a little experience of Telltales’ games, but from their pre-TWD period when the games they produced (such as the licensed Back to the Future and their first episodic title, Sam and Max: Season One).