Successfully complete the indicated task in Scenario Campaign mode to unlock the 
corresponding stage:

Arena: Successfully complete Southern Woodlands. 
Kigan Island: In Abyss Gate on the Hard difficulty, defeat a man with straw 
hat, take his items, then exit to the world map. 
Mishima Industries, Biotech Research Station Ruins: Go right at the first 
junction in Seahorse Grand Hotel. Then, defeat the Kangeroo, and complete the 
stage. 
Nightmare Train: Successfully complete Azazel's Temple, Central Corridor. 
Subterranean Pavilion: Successfully complete 16th Archaeological Expedition's 
Excavation Site on the Hard difficulty.