Sonic Mach2 has been listed by Romanus Fuhrman on his website, who is Orbot’s German voice actor:

sonic mach2

computerspiel von sega

rolle: orbot

regie: ilja köster | iksample stud Translated:

Sonic Mach2

Video game by Sega

role: Orbot

regie: ilja köster | iksample stud

Someone then sent a message to Takashi Iizuka’s facebook for some answers, who responded with the following:

Could Sonic Mach2 be the next Sonic game? It certainly seems quite likely at this point. The long term silence regarding any new Sonic games has been broken. Let us know what your thoughts are in the comment section below!