Mother May I?

Defeat the Mother of All Demons on The Absolution

150 Gamerscore

Walk the Path

Finish the Lost Levels mission

125 Gamerscore

Secret Sleuth

Discover a secret area

50 Gamerscore

My Cause is Just, My Will is Strong

Find the BFG9000

50 Gamerscore

Unholy Firepower

Find the Unmaker

75 Gamerscore

Persistence is the Key

Acquire all 3 Demon Key Artifacts in the main campaign

125 Gamerscore

Rip and Tear!

Kill a Cyberdemon

100 Gamerscore

That was Fun

Finish a 'Fun' Level

100 Gamerscore

RVNH3CT1CD3M0???

Locate the secret level 'Hectic'

100 Gamerscore

Escape Artist

Finish 'No Escape' on Watch Me Die! skill level

125 Gamerscore