Cheats for Sonic 1

Source: https://gamefaqs.gamespot.com

Level Select:

up, down, left, right, press start while holding A

Debug Mode:

up, C, down, C , left, C, right, C, press start while holding A

Cheats for Sonic the Hedgehog 2

Source: https://gamefaqs.gamespot.com

Level Select:

First, go to Options. Play the following music and sounds in the sound test:

19, 65, 09, 17

You should hear a ring-chime. Now press START to return to the title screen. Highlight 1-Player, hold A and press START.

You should the see the Level Select Screen. Press Start to enter a stage.

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