Overview
This is a guide on how to unlock all three new multiplayer achievements introduced by Update 6.66.
On Track
Go into your Multiplayer Profile menu, the Challenges section. Find the challenge you’re closest to completing, select it, and press enter. A little gold eyeball icon and a gold frame will adorn the challenge, signifying it is a tracked challenge. It will show up on the right side of your in-game multiplayer HUD, and when you complete it, you’ll get the achievement.
I have to credit EsotericHarmony for explaining this one to me in her guide.
A Memorable Performance
Earn a Gold Medal Rating in a Multiplayer match to get this trophy. I actually got this one by accident in a Freeze Tag match, mostly by Thawing and Multi-Thawing teammates en masse, and getting a few kills in too. In fact, I got my first Slayer rating on that Freeze Tag match for that. So try doing that in a Freeze Tag match, and you should get the achievement.
Slotted for Success
You get this achievement for unlocking all the multiplayer runes. You unlock runes for leveling up in Multiplayer. Once you reach level 44 in Multiplayer, you’ll unlock the last rune. So just keep scoring as high as you can and completing as many challenges as you can in as many multiplayer matches as you can, and you’ll eventually level up enough to unlock the achievement.