The game is Sonic Sms Remake.Fantastic remake the sonic Master Sytem/Game Gear. : r/SonicTheHedgehog

Sonic 1 Remake (Master System) - Download #13

The Sonic SMS Remake Collection

Custom / Edited - Sonic the Hedgehog Customs - Sonic 3 (Master System-Style) - The Spriters Resource

game gear « SEGADriven

SONIC SMS REMAKE, O INCRÍVEL REMAKE DO SONIC DE MASTER SYSTEM

Sonic SMS Remake: Sonic 1 - v1.0.F

Creative Araya's 8-bit Sonic fan remakes are impressive (Android and Windows)

Why does SEGA keep forgetting that the Master System ever existed? : r/ SonicTheHedgehog

SAGE 2023 - Complete - Sonic SMS Remake (60 FPS + 2P)

Sonic SMS Remake

What version of Sonic the Hedgehog (1991) do you think is the best? The Genesis/Mega Drive version, the Master System/Sega Mark III version, the Game Gear version, or the Tiger Electronics version? : r/SonicTheHedgehog

A full, fan made 16-bit reimagining of Sonic Triple Trouble just released today, and it's pretty great, Page 3