Some of the Cyberspace levels have layouts and elements taken almost directly from previous Sonic games, even if the aesthetics of the Cyberspace levels don't match the legacy ones at all sometimes. They are as follows:

Zone 1-1: Windmill Isle Act 1 from Sonic Unleashed

Zone 1-2: Windmill Isle Act 2 from Sonic Unleashed

Zone 1-4: Green Hill Act 2 from Sonic Generations

Zone 1-5: Chemical Plant Act 2 from Sonic Generations

Zone 1-6: Green Hill Act 1 from Sonic Generations

Zone 1-7: City Escape from Sonic Adventure 2

Zone 2-1: Green Hill Act 2 from Sonic Generations (2D sections)

Zone 2-2: Dragon Road Act 3 from Sonic Unleashed

Zone 2-4: Shadow's Radical Highway level from Sonic Adventure 2

Zone 2-5: Sky Sanctuary Act 2 from Sonic Generations (2D sections)

Zone 2-6: Shadow's Sky Rail level from Sonic Adventure 2

Zone 2-7: Sky Sanctuary Act 1 from Sonic Generations

Zone 3-1: Green Forest from Sonic Adventure 2

Zone 3-2: Savanna Citadel Act 1 from Sonic Unleashed

Zone 3-3: Sky Sanctuary Act 2 from Sonic Generations (3D sections)

Zone 3-6: Rooftop Run Act 2 from Sonic Unleashed

Zone 3-7: Chemical Plant Act 2 from Sonic Generations (2D sections)

Zone 4-1: Metal Harbor from Sonic Adventure 2

Zone 4-6: Chemical Plant Act 1 from Sonic Generations