Enable Debug mode. At the beginning of Emerald Hill Act 2, switch to debug mode and spawn lots of waterfalls until the lives icon goes black and green. Note: there are many variations of Ashura that are possible.
Ashura is not Sonic's brother, he is a palette mistake when debug mode is entered in Sonic 2. By placing waterfalls down in Emerald Hill zone Sonic will change colour, into a green hedgehog with black on his head, fans dubbed this new creation Ashura.
12: Sonic the Hedgehog Sonic the Hedgehog 2 Sonic Chaos/Sonic & Tails Sonic the Hedgehog Spinball Dr. Robotnik's Mean Bean Machine Sonic Drift Sonic Triple Trouble/Sonic & Tails 2 Sonic Drift 2 Tails Adventure Sonic Labyrinth Tails' Skypatrol Sonic Blast
after sonic the hedgehog for the sega genesis it's sonic the hedgehog 2
Sonic the Hedgehog 2 (1992)
Sonic the Hedgehog Sonic the Hedgehog 2 Sonic the Hedgehog 3 Sonic & Knuckles Sonic the Hedgehog Spinball Dr. Robotnik's Mean Bean Machine Sonic 3D Blast Sonic CD Sonic Eraser SegaSonic Cosmo Fighter (Japan only) Segasonic the Hedgehog (Japan only) Sonic Chaos/Sonic & Tails (Japan only) Sonic Triple Trouble/Sonic & Tails 2 (Japan only) Sonic Drift Sonic Drift 2 Sonic Blast Tails' Skypatrol Tails Adventure Knuckles' Chaotix Sonic Jam Sonic R Sonic Adventure Sonic the Hedgehog Pocket Adventure Sonic Shuffle Sonic Adventure 2 Sonic Mega Collection Sonic Advance Sonic Advance 2 Sonic Advance 3 Sonic Heroes Shadow the Hedgehog Sonic Riders Sonic Riders: Zero Gravity Sonic Free Riders Sonic Rush Sonic the Hedgehog (Xbox 360/PS3) Sonic Rivals Sonic and the Secret Rings Mario & Sonic at the Olympic Games Mario & Sonic at the Olympic Winter Games Sonic Unleashed Sonic Chronicles: The Dark Brotherhood Sonic and the Black Knight Sonic Classic Collection Sonic the Hedgehog 4 Sonic Colors
Ashura is not Sonic's brother, he is a palette mistake when debug mode is entered in Sonic 2. By placing waterfalls down in Emerald Hill zone Sonic will change colour, into a green hedgehog with black on his head, fans dubbed this new creation Ashura.
1:Sonic the Hedgehog 2 2:Sonic Adventure DX 3:Sonic Advance 2 4:Sonic 3 & Knuckles 5:Sonic the Hedgehog 5: Sonic the Hedgehog 4: Sonic Advance 3 3: Sonic Adventure 2: Sonic & knuckles 1: Sonic CD 5: Sonic the Hedgehog 3 4: Sonic the Hedgehog 3: Sonic the Hedgehog (2006) 2: Sonic and the Secret Rings 1: (what? not sonic cd?) Sonic Adventure
The Sonic the Hedgehog game franchise has these games: Sonic the Hedgehog, Sonic the Hedgehog 2, Sonic the Hedgehog Spinball, Sonic the Hedgehog 3, Sonic & Knuckles, Sonic Adventure, Sonic Adventure 2 Battle, Sonic Advance, Sonic Mega Collection, Sonic Heroes, Sonic Mega Collection Plus, Sonic Rush, Sonic and the Secret Rings, Sonic the Hedgehog (mobile), Sonic Unleashed, Sonic & Sega All-Stars Racing, Sonic Colors, and Sonic Generations.
12: Sonic the Hedgehog Sonic the Hedgehog 2 Sonic Chaos/Sonic & Tails Sonic the Hedgehog Spinball Dr. Robotnik's Mean Bean Machine Sonic Drift Sonic Triple Trouble/Sonic & Tails 2 Sonic Drift 2 Tails Adventure Sonic Labyrinth Tails' Skypatrol Sonic Blast
it's (sonic the hedgehog) and (shadow the hedgehog) and (silver the hedgehog)
As of 2011: Sonic the Hedgehog Sonic the Hedgehog 2 Sonic the Hedgehog CD Sonic Spinball Sonic the Hedgehog 3 Sonic & Knuckles Sonic Labyrinth Sonic 3D Blast (Flickie's Island) Sonic R Sonic Adventure Sonic Pocket Adventure Sonic Shuffle Sonic Adventure 2 Sonic Advance Sonic Advance 2 Sonic Battle Sonic Heroes Sonic Advance 3 Shadow the Hedgehog Sonic Rush Sonic Riders Sonic the Hedgehog (2006) Sonic and the Secret Rings Sonic Riders Zero Gravity Sonic Chronicles: The Dark Brotherhood Sonic Unleashed Sonic and the Black Knight Sonic the Hedgehog 4: Episode 1 Sonic Free Riders Sonic Colours Sonic Generations
after sonic the hedgehog for the sega genesis it's sonic the hedgehog 2
Sonic the Hedgehog (1991) Sonic the Hedgehog (8-bit) Sonic the Hedgehog 2 Sonic the Hedgehog 2 (8-bit) Sonic Chaos Sonic Spinball Sonic CD Sonic the Hedgehog 3 Sonic & Knuckles Sonic Drift Sonic Triple Trouble Sonic Drift 2 Sonic 3D Blast Sonic Blast Sonic the Fighters Sonic R Sonic the Hedgehog Pocket Adventure Sonic Adventure Sonic Shuffle Sonic Adventure 2 Sonic Adventure 2 Battle Sonic Advance Sonic Advance 2 Sonic X (Leapster) Sega Superstars Sonic Battle Sonic Advance 3 Sonic Rush Sonic Rush Adventure Sonic Pinball Party Sonic Adventure DX Sonic Heroes Shadow the Hedgehog Sonic Riders Sonic the Hedgehog (2006) Sonic Rivals Sonic and the Secret Rings Sonic Rivals 2 Mario & Sonic at the Olympic Games Sonic Riders: Zero Gravity Super Smash Bros. Brawl Sonic Chronicles: The Dark Brotherhood Sonic Unleashed Sonic and the Black Knight Mario And Sonic At The Olympic Winter Games Sonic & SEGA All-Stars Racing Sonic Classic Collection Sonic the Hedgehog 4 Episode I Sonic Free Riders Sonic Colors Sonic Generations Mario And Sonic At The 2012 London Olympic Games Sonic The Hedgehog 4 Episode II Sonic The hedgehog 4 Episode Metal Sonic & All Stars Racing Transformed
Sonic the Hedgehog 2 (1992)
There isn't one that is just Sonic the hedgehog 2, but there is the Sonic Classic Collection which has 1,2,3, and Sonic & Knuckles
Sonic the Hedgehog Sonic the Hedgehog 2 Sonic the Hedgehog 3 Sonic & Knuckles Sonic the Hedgehog Spinball Dr. Robotnik's Mean Bean Machine Sonic 3D Blast Sonic CD Sonic Eraser SegaSonic Cosmo Fighter (Japan only) Segasonic the Hedgehog (Japan only) Sonic Chaos/Sonic & Tails (Japan only) Sonic Triple Trouble/Sonic & Tails 2 (Japan only) Sonic Drift Sonic Drift 2 Sonic Blast Tails' Skypatrol Tails Adventure Knuckles' Chaotix Sonic Jam Sonic R Sonic Adventure Sonic the Hedgehog Pocket Adventure Sonic Shuffle Sonic Adventure 2 Sonic Mega Collection Sonic Advance Sonic Advance 2 Sonic Advance 3 Sonic Heroes Shadow the Hedgehog Sonic Riders Sonic Riders: Zero Gravity Sonic Free Riders Sonic Rush Sonic the Hedgehog (Xbox 360/PS3) Sonic Rivals Sonic and the Secret Rings Mario & Sonic at the Olympic Games Mario & Sonic at the Olympic Winter Games Sonic Unleashed Sonic Chronicles: The Dark Brotherhood Sonic and the Black Knight Sonic Classic Collection Sonic the Hedgehog 4 Sonic Colors
Sonic Adventure 2, Sonic Battle, Sonic Heroes, Sonic The Hedgehog (Sonic '06), Sonic Rivals, Sonic Rivals 2, Sonic Chronicles: The Dark Brotherhood, lastly Sonic and the Black Knight (as Lancelot).