Playable characters are characters that you can play as
Originally only Arthur was playable, but in Gargoyles Quest, you play as a Red Arremer named Firebrand, in Maximo: Ghosts to Glory, you play as a brave knight named Maximo
In Ghosts 'n Goblins: Gold Knights, not only could you play as Arthur, but you could also play as Lancelot, then in the sequel you can play as Perceval