How the stage works
Momentum and a following camera.
The Java engine keeps the original fixed-point movement, slope sensors, rolling, jumping and camera windows. Sonic moves in world coordinates; the screen follows after he crosses its tracking window. The distant scenery scrolls at the original separate rates.
Java source and fidelity notes ↗ · Download source ↗
Tested first-act reconstruction
From start to signpost.
The verified route runs through the whole act and reaches the results tally with cheats off. Original placement data supplies all 214 objects and 155 rings. Movement, terrain, objects and animation have separate comparisons with the supplied ROM.
This page contains Act 1. Later acts and the special stage are outside this build. Tested comparisons do not prove every possible playthrough is identical to the Genesis game. Lighting and weather are new visual effects.
Verification record ↗