grown man dressed as Captain Falcon; that's kind of disturbing." Fairly innocent, right? The connotation we would associate with the Silent Hill costumes pictured above is a little more direct, as in: "Those Silent Hill costumes are disturbing." Given the arc of the franchise though, we suppose that's the point.
Seen at Anime Central 2009 (photos by Judith Stephens) the costumes are frighteningly accurate recreations of the both Pyramid Head and a nurse from the Silent Hill series (and are based on the film versions of those characters by the looks of things). Hit the source link for lots more pictures, and possibly a few nightmares.
Those with weaker stomachs would probably be better served by the Pyramid Head snowman, which is almost cute.