Sony Computer Entertainment's Knack has unlockable versions of the namesake character that players can access if they collect the right number and kinds of relics, game director Mark Cerny revealed today on the PlayStation Blog.
In the game, the default version of Knack allows him to incorporate ice, metal and other substances into his body to give him new abilities from level to level. The unlockable characters build on this by giving him different properties based on the kinds of relics the player collects.
Collecting 15 Ruby relics will unlock Vampire Knack, who has stronger attacks but also loses health as he fights. As his name suggests, he can replenish his health by defeating enemies and sucking their energy into himself.
Collecting Emerald relics will unlock Massive Knack, who is incredibly strong but can only store one super move's worth of energy. Aquamarine relics will unlock Brittle Knack, who has powerful punches, kicks and dash attacks, but shatters easily when hit.
Amethyst relics will unlock Dark Knack, who has strong defenses, while Sunstone relics will unlock Sunstone Knack, whose super moves last longer and do more damage. The rarest Knack can be unlocked through Diamond relics, who is stronger and tougher in every way.
Cerny goes into further detail of the unlockable Knacks and the game's two special challenge modes in the blog post.