| Unlockable: | How to Unlock: |
| 01 Cpt. Devin Ross | Kill 50 enemies using melee attacks |
| 02 Lt. Abigail Black | Kill 50 enemies using Ghost Bullet |
| 03 Sgt. Frank Delgado | Pop 50 heads! |
| 04 Sgt. Wilhelmina "Billie" Church | Complete "Al Khali" on hard |
| 05 Cpt. Xavier Jones | Complete "Man Down" on hard |
| 06 Cpl. Simone Cole | Complete "The Tomb" on hard |
| 07 Fr. Paul Rawlings | Pop 100 heads! |
| 08 Agent Muriel Green | Complete "The Den of Souls" on hard |
| 09 Arnold Leech | Complete "Al Khali" on either easy or normal |
| 10 Deceased Devin Ross | Complete "Still With You" on hard |
| 11 Cultist | Kill 100 enemies using melee attacks |
| 12 Exlposive Cultist | Disintegrate 50 enemies! |
| 15 Corpses Behemoth | Complete "River of Blood" on hard |
| 17 Psychic Commander | Complete "World War 2" on either easy or normal |
| 19 Flamethrower | Disintegrate 100 enemies! |
| 20 Grenadier | Kill 100 enemies using Ghost Bullet |
| 21 Sir Richard de Gray | Complete "Out of the Frying Pan" on hard |
| 22 Brother William of Auxere | Complete "Motley Crew" on hard |
| 23 Warrior Crusader | Complete "Sewers" on hard |
| 24 Crossbowman Crusader | Complete "Tortured Souls" on hard |
| 25 Child Crusader | Complete "Crusades" on either easy or normal |
| 26 Bishop Malthus St. Claire | Complete "Crusades" on either easy or normal |
| 27 Centurion Textius Longinus | Complete "Decadence" on hard without being incapacitated |
| 28 Governor Cassus Vicus | Complete "Rome"on either easy or normal |
| 29 Legionary | Complete "The Low Road" on hard |
| 30 Blind Behemoth | Complete "Morituri te salutant" on hard without being incapacitated |
| 31 Gladiator | Complete "Temple of Pain" on hard |
| 32 Antadurunnu | Complete "The God Seal" on hard |
| 33 Enlil | Complete "Spiritual Guide" on hard |
| 34 Inanna | Complete "Skin" on hard |
| 35 Ki | Complete "Flesh" on hard |
| 36 Ninlil | Complete "Skin" on hard without being incapacitated |
| 37 Nanna | Complete "Blood" on hard |
| 38 Utu | Complete "Blood" on hard without being incapacitated |
| 39 Sumerian Puppet | Complete "Flesh" on hard without being incapacitated |
| 40 Pyxis Prima | Complete "Sumeria" on either easy or normal |
| 42 The Jericho Team | Complete "Rivers of Blood" on hard without being incapacitated |
| 43 Operation: Godseal | Complete "Exorcism" on hard |