The engine has evolved from v3 (Sonic CD) to v4 (Sonic 1/2 Mobile) and finally, v5/v5U (Sonic Mania/Origins).
This is the most popular "RSDK-style" version of the game. While it doesn't use the actual RSDK engine, it was built by developer to look and feel exactly like Whitehead's remasters. Requirement : You must provide your own legal Sonic 3 & Knuckles ROM (usually from Sonic 3 Rsdk
The RSDKv5U decompilation includes an advanced, built-in mod loader, similar to Sonic Mania . This makes it incredibly easy to: The engine has evolved from v3 (Sonic CD)
When official development stalled, the Sonic hacking and engineering communities took matters into their own hands. Multiple distinct efforts emerged under the "Sonic 3 RSDK" umbrella, attempting to recreate or backport the game using Whitehead's framework. 1. The Sonic 3 '14 Project (The RSDKv4 Proof-of-Concept) Requirement : You must provide your own legal