 The game began development shortly after the 2010 release of Sonic Colors . It was designed to be streamlined , simple , and fluid in movement and design , using a novel tube @-@ like level design style and a simple , bright color scheme . The game received mixed reviews upon release ; its controls and the Deadly Six were frequently criticized , but its visuals and audio were seen positively . Downloadable content was released both alongside and after the game 's release , adding features such as additional levels and a new type of Wisp power . 
