Super Smash Bros. Brawl by ripping the game code and editing the textures to look like other well-known Nintendo costumes -- like Fierce Deity Link as he appeared in The Legend of Zelda: Majora's Mask. Pikachu becomes Plusle and Minun, Lucas becomes a juvenile Phoenix Wright, Ness becomes Zim, and R.O.B. becomes ... R.O.B. covered in blood. It looks like it came out of a Funcoland in Silent Hill.
The Ghosteo posters aren't releasing the textures to the public until they've completed two per character, if at all. So for now all we can do is imagine what it must be like to play Brawl as Sonic, but ... looking like Metal Sonic.