Batman: Arkham Origins

- There are set of challenges to do in the main game. They have to be done sequentially, and they unlock various abilities (as well as XP). The combat and the exploration challenges are fairly straightforward but the predator ones are fucked. If you want to do them in one playthrough, use a guide. Several of the challenges can only be done in a handful of locations, and if you miss them you'll delay the whole lot and have to wait until much later and NG+.