It's a fan game, developed on Sonic Worlds engine by Strife.
The main feature of the project is that it's based on Sonic game mechanics and character style, but the universe where the game takes place and the characters are created by the author. The main character is a fan-character of DA user Ziyo Ling, Sash Lilac (she even has a fan group at deviantART).
5 zones are planned in the game; one of them is already finished.
Dragon Valley - Finished Relic Maze Robot Playground Battle Glacier Thermal Base
Also the author plans adventure fields and story cutscenes.
Some artwork from the author:
Sash Lilac - the main character
Spade the Cavy - the rival of the main character. Uses a deck of cards as a weapon.
Dr. Brevon (concept) - main antagonist
One of the bosses
Three more characters - two good guys and one evil girl
Screenshots
Video
http://www.youtube.com/watch?v=VR1DkC6RQAQ http://www.youtube.com/watch?v=WtQOY0R47LY