Re: vast open world games
7 Days to Die. It's as vast as you can stomach, there is next to no story to bother you, and there are very few bugs.
It's just you against a zombie world, and you have a number of ways to try to survive.
And, in the latest version, there is some parkour to be had - although you can't just go and climb vertical walls. But you can create a ladder to get to the roof.