Is Sonic generations all the Sonic the Hedgehog games

Sonic Generations is not ALL of the Sonic the Hedgehog games. The games represented in Sonic Generations for Xbox and PS3 are: Sonic the Hedgehog (Green Hill Zone), Sonic the Hedgehog 2 (Chemical Plant), Sonic & Knuckles (Sky Sanctuary), Sonic Adventure (Perfect Chaos & Speed Highway), Sonic Adventure 2 (City Escape), Sonic Heroes (Seaside Hill), Sonic the Hedgehog (2006) [Crisis City], Sonic Unleashed (Rooftop Run), and Sonic Colors (Planet Wisps).

The 3DS version features different levels from the Sonic Series: Sonic the Hedgehog (Green Hill Zone), Sonic the Hedgehog 2 (Casino Night), Sonic & Knuckles (Mushroom Hill), Sonic Adventure (Emerald Coast), Sonic Adventure 2 (Radical Highway), Sonic Heroes (Water Palace and Special Stage), and Sonic Colors (Tropical Resort)