DOOM 64

Mother May I?

Defeat the Mother of All Demons on The Absolution

Walk the Path

Finish the Lost Levels mission

Secret Sleuth

Discover a secret area

My Cause is Just, My Will is Strong

Find the BFG9000

Unholy Firepower

Find the Unmaker

Persistence is the Key

Acquire all 3 Demon Key Artifacts in the main campaign

Rip and Tear!

Kill a Cyberdemon

That was Fun

Finish a 'Fun' Level

RVNH3CT1CD3M0???

Locate the secret level 'Hectic'

Escape Artist

Finish 'No Escape' on Watch Me Die skill level