Complete the indicated task to unlock the corresponding stage. Note: Levels must be unlocked separately for each Extra Content type (Mercenaries, Siege, Predator, etc.)

Stage 4: Rail Yard: Complete Mining the Depths with a "B" rank.
Stage 5: High Seas Fortress: Complete Rail Yard with a "B" rank.
Stage 6: Catacombs: Complete High Seas Fortress with a "B" rank.
Stage 7: Requiem for War: Complete Catacombs with a "B" rank.
Stage 8: Liquid Fire: Complete Requiem for War with a "B" rank.
Stage 9: Rooftop Mission: Complete Liquid Fire with a "B" rank.
Stage 10: Creature Workshop: Complete Rooftop Mission with a "B" rank.