Rescuing other prisoners
A big part of the game will be rescuing other prisoners and sending them back up to the surface. This is a glimpse on what the mechanic might look like. Ideally there will be elevators or trains that take prisoners away from you so you aren't escorting them too long. It's your job to defend them, and you will be rewarded for how many prisoners you can escort out of the mine.
As far as rewards go, that is mostly undetermined. Maybe something like larger weapon ammo capacity, or max health increases. Something less important to progression, but still impactful.