Coffin: Dairy PlantG 20

Can be done any time, but easier to locate once you've unlocked the MAP by finding the MILKY WAY MAP relic in the Dairy Plant. Coffins will be marked by a large white question mark (?) on the pause map.

When:
You must have reached level 40 on the second map to unlock the Dairy Plant.

Method:
As soon as you spawn, pause the game and look at the map. start heading towards the question mark - it's a long walk! Keep walking a until you reach the obvious coffin. Destroy the circle of enemies which spawn around the coffin, then walk into it to unlock a new character, and...

...Achievement unlocked!