Cheat Codes - Sonic the Hedgehog 2 (Megatech) - Sonic Retro

Sonic The Hedgehog 2 cheat for Mega Drive/Genesis - Level Select (with save state for emulators)

Sonic the Hedgehog 2 (16-bit)/Hidden content - Sonic Retro

Sonic the Hedgehog 2-Game Secrets & Tips(Cheat Codes)

Sonic 2 Level Select & Debug Mode Guide, PS4, Switch & XB1

Gamers go wild for Sonic Origins Plus cheat codes – Hidden Palace Zone, Super Sonic and more

Xbox 360 Cheats - Sonic 4 Guide - IGN

Sonic the Hedgehog 3 & Knuckles, A Gamer's Cheat Codes Wiki

4 Steps to Use Cheats in Sonic Mania Plus - KeenGamer

Sonic the Hedgehog 2 (Mega Drive) - The Cutting Room Floor

The List of Every Cheat Code in Sonic Origins