Sonic Team vice president of product development Takashi Iizuka has clarified the question of the newly unveiled Sonic Superstars’ main developer: it’s being led by Arzest, the Japanese studio which recently co-developed Fantasian and the troubled Balan Wonderworld – and that’s headed up by Sonic’s original creator Naoto Ohshima.
Source: N4G PC Balan Wonderworld co-dev Arzest is "leading development" on Sonic Superstars