Sonic Night Edition (S1 Hack) is a ROM hack, specifically modifying the first Sonic game. It likely features altered level designs, potentially new graphics or music, all within the context of the original game's mechanics.  The 'Night Edition' moniker might suggest a visual theme or atmosphere change to the levels.  To determine the precise alterations and gameplay changes, dedicated research into Sonic ROM hacking communities is recommended.

Sonic Night Edition (S1 Hack)

Sonic Netinirvana