The side quests pop up based on location for the most part. But the story only gets deep if you do a lot of those quests. The romances and friendships are side quests for the most part. The stories you uncover. I want mention specifics, but a fan favorite involves a couple of rich politicos that call you. The weird shit you find out with the cyberpsycho quests are pretty neat.

This doesn't have a KOTOR light side dark side meter, but if you start to connect with your character, then some of the choices you make are rather emotional. Like you get hired to kill someone, but they talk to you when you get there and you have to decide what to do. And sometimes that changes some things later.

I played all of the original endings (I have about 300 hours in the game since launch). Prior to Phantom Liberty, I decided to try a certain ending and it absolutely crushed me. I was legitimately angry at some of the people and crying about how things went for some others.

If you just want an action rpg light on the story, this isn't it. This is like getting to jump into the action of a really interesting comic series. Lots of shit going on that isn't the main focus of the story. Some of it matters and some of it is just something to do. I imagine if you only hit the main storyline it'd probably be kind of bland. For one, you want have a good reason to kill every tiger claw that you see.