I think what I really loved about Crackdown - and what is still so rare in open world games - is that you had to actually climb buildings through platforming, so there was a real sense of achievement when you reached the top, or a balcony or ledge with a hidden orb. Games like Prototype, Infamous and Spider-Man etc - they let you run (or swing) up towers but it's not the same. Just simply running up a building as if it's the ground provides no sense of achievement when you get there, and no sense of wonder when you're at the bottom looking up wondering if there might be a hidden orb up there.
It's where BotW particularly excelled - rather than just being able to run up any mountain, you had to figure out a way to get up there. It made it so much more rewarding when you did, and provided so much more of a sense of wonder as you explore the environment.
