- Back to: Sonic the Hedgehog 3 & Knuckles.
After work was completed on the "first part" of Sonic the Hedgehog 3, the developers mainly concentrated on finishing the remaining stages - those which would appear in Sonic & Knuckles. While one might assume the locked-on Sonic the Hedgehog 3 & Knuckles would just bridge the gap (and let Tails/Knuckles play in Sonic & Knuckles and Sonic 3 levels, respectively), Sonic & Knuckles also acts as a "patch" to Sonic 3, fixing several of its bugs and also making adjustments to levels to increase or decrease difficulty.
Most importantly, code in Sonic & Knuckles finishes the Sonic 3 routes intended for Knuckles. From the very beginning, Sonic 3 stages were designed with Knuckles-only areas (visible in that game through edit mode), but progress was put on hold when the game was split in two.
Sonic the Hedgehog 3 & Knuckles favours the Sonic 3 title screen and menu system, but substitutes the Sonic 3 jingles, Knuckles and boss music for their Sonic & Knuckles counterparts. The title screen is amended as the game's name has now changed.
The Data Select gets extra information for lives and continues. The number of save slots also increases from 6 to 8.
All title cards are amended to show Sonic 3 & Knuckles.
The level select is expanded to include all the Zones, culling the Competition Mode levels and the Sonic 2 level icons in the process. The Sonic & Knuckles level select screen is identical, just with half of the levels disabled.
Giant Rings in Sonic & Knuckles stages become a means of teleporting to Hidden Palace Zone to obtain Super Emeralds.
The palette for Sonic 3's hidden eighth Special Stage was changed.