Zu is another female one, but it must be unlocked. You can also choose to play with Zeta the Echidna, an original character, a cartoon portrayal of the main developer. Here you can't play as Sonic, instead you get a bunch of secondary characters (almost all female, except Tails) from the Sonic the Hedgehog universe: Miles 'Tails' Prower, Amy Rose, Rouge the Bat, Blaze the Cat and Cream the Rabbit.
2008 indie erotic Sonic platform fighting game by The Zeta Team, unrelated to Sega and the Sonic Team.
