For starters, Epic will be launching achievements in Rocket League, Hades, Pillars Of Eternity, Kena: Bridge Of Spirits, Zombie Army 4, Alan Wake Remastered, "and more". Each game achievement has an XP value from 5-250, and an associated Bronze through Platinum rating attached. As for what they're good for, well, looking at of course. That's why folks like cheevos, right?