…Two Steps Back ' & 'Sonic Generations.' 'Genesis' may be over, but Sonic's 20th Anniversary celebration parties on! As the Genesis Epilogue unfolds, the Death Egg II still menaces New Mobotropolis, and Dr. Eggman has one more sinister trick up his sleeve. It's a desperate race against time as Sonic and Sally try to prevent another world catastrophe, and the ending will leave you speechless. Also featuring a very special Sonic Generations video game story!