What's done?

Legend:

O: Means it is seen in Beta.

Finished

Sonic 1
Green Hill Zone Act 1 O
Green Hill Zone Act 4 (Beta GHZ) O
Marble Zone Act 1 O
Marble Zone Act 4 (Beta MZ) O

Sonic 2
Emerald Hill Zone Act 1
Wood Zone (Boss missing in Act 2) O
Genocide City Zone (Boss missing in Act 2) O
Hidden Palace Zone O
Dust Hill Zone Act 1 O

Sonic 3 & Knuckles
None

Sonic Crackers
Not even started

Half complete

Sonic 1
Labyrinth Zone Act 1
Final Zone

Sonic 2
Chemical Plant Zone Act 1

Sonic 3 & Knuckles
...

half started

Sonic 1
Green Hill Zone Act 2
Sparkling Zone (Beta name for Spring Yard)
Star Light Zone Act 1
Clock (W)ork Zone Act 1 (Beta name for Scrap Brain)

Sonic 2
Aquatic Ruin Zone Act 1
Casino Night Zone Act 1
Hill Top Zone Act 1
Death Egg Zone

Sonic 3 & Knuckles
Hydrocity Zone
Marble Zone
Carnival Night Zone
Launch Base Zone
Sky Sanctuary Zone