3 cheat codes for Sonic the Hedgehog 2 on Genesis.
In the Options menu's Sound Test play those sounds in order — a ring chime confirms. Then return to the title screen and hold A + press Start. The numbers are Yuji Naka's birthday (17 Sep 1965).
19, 65, 09, 17 (Options sound test)Turn on the console with no cartridge-locked menus needed — the codes below are entered on the title screen or in the Options menu as described per entry. Original Genesis/Mega Drive version.
After unlocking Level Select, play those sounds on its Sound Test, then select any Zone, hold A and press Start. B toggles debug mode.
01, 09, 09, 02, 01, 01, 02, 04 (Level Select sound test)Turn on the console with no cartridge-locked menus needed — the codes below are entered on the title screen or in the Options menu as described per entry. Original Genesis/Mega Drive version.
Play those sounds on the Level Select sound test (you hear the Chaos Emerald jingle), then pick any level, collect 50 rings and jump — you transform immediately.
04, 01, 02, 06 (Level Select sound test)Turn on the console with no cartridge-locked menus needed — the codes below are entered on the title screen or in the Options menu as described per entry. Original Genesis/Mega Drive version.