Kill one of every enemy.
Reach the end of 'Legacy of Rust'.
Obliterate 50 enemies with a single shot of the Calamity Blade.
Immolate a total of 30 arachnoid enemies with the Incinerator.
Reach the end of 'Sigil'.
Reach the end of 'No Rest for the Living'.
Reach the end of 'The Plutonia Experiment'.
Reach the end of 'TNT: Evilution'.
Reach the end of 'Master Levels for DOOM II'.
Reach the end of 'DOOM II'.
Reach the end of 'DOOM'.
Finish off a Cyberdemon with the Pistol.
Get 100 Chainsaw kills.
Complete 8 different levels sequentially under par time without dying on Ultra-Violence or higher.
Kill 4 enemies in 1 shot with the Super Shotgun.
Finish a level with 200% armor and 200% health.
Gib three or more enemies with a single rocket explosion.
Kill 5 enemies in 5 seconds with the Plasma Rifle.
Find a secret level.
Complete a level on Nightmare difficulty.
Crush a corpse in a door.
Get 3 multi-kills with the Shotgun.
Kill 2 enemies with a single barrel explosion.
Shoot 200 bullets consecutively with the Chaingun.
Kill only a single enemy with a BFG9000 blast.
Finish a level with 100% items picked up.
Complete any monster-filled level with 100% kills without getting hurt on Ultra-Violence or higher.
Complete any monster-filled level with 100% kills, items, and secrets.
Kill all monsters in any monster-filled level on 'Hurt me plenty' or higher.
Get 25 kills with your Fists in a single level.
Find a secret area.
Get 20 kills using the berserk powerup in a single level.
Cause an enemy to kill another enemy.
