The list below chronicles all of the hidden, unlockable characters in the game, and how each one is unlocked.

• Alien Hominid - Have the full game of Alien Hominid HD on your Xbox 360's HDD and get at least one achievement in it.
• Barbarian - Beat King's Arena.
• Bear - Beat the game with Skeleton.
• Beekeeper - Beat the game with The Barbarian.
• Black Knight - Beat the Game with Grey Knight.
• Brute - Beat the game with The Eskimo.
• Civilian - Beat the game with Peasant.
• Commoner - Beat game with peasant knight.
• Eskimo - Complete Icy Arena offline.
• Fencer - Beat the game with Mechanic.
• Forest Knight - Beat the game with the Thief.
• Grey Knight - Defeat the Barbarian Boss.
• Mechanic (Gear Knight) - Beat the game with Blue Knight.
• Ninja - Beat the game with The Red Dragon Knight.
• Peasant - Complete the "Peasant Arena".
• Periwinkle Knight - Complete the "Volcano Arena".
• Red Dragon Knight - Beat Game With Orange Knight.
• Royal Guard - Complete the game as Green Knight.
• Skeleton - Complete the game as Red Knight.
• Thief - Beat Thieve's Arena.