These are the listed levels in the games.
Monster Defenders Levels[]
Level 1: Monster High
Level 2: Prarie Field
Level 3: Auroma Yard
Level 4: Phantom Forest
Level 5: Forest Hydra Attack
Level 6: Junkyard Isles
Level 7: Golden town
Level 8: Yellowfields
Level 9: Haystack Lake
Level 10: Hay Golem Disaster
Level 11: Tundra
Level 12: Arrowhead Lake
Level 13: Iceberg Tower
Level 14: Aurora Bluefires
Level 15: Galice Rampage
Level 16: Gygabyte World
Level 17: Data Base
Level 18: Electric Pits
Level 19: Enemy Headquarters
Level 20: The Legend of Mart
Level 21: Hidden Island
Level 22: Robot Village
Level 23: Black Base
Level 24: Radius Territory
Level 25: The Evil Trio
Level 26: Radius Throne @
Final Level: Radius Boss Fight @
Bonus Level: Eruption @
@ = You can't access these levels until you have every defender on the team.