How do you submit codes on Sonic 2?
Games Guru: Go to the options menu and select the Sound Test Option. The best codes in Sonic 2 involve listening to sounds in the right order. You can give yourself 14 continues by listening to sound tests 1, 1, 2 and 4, then pressing start.
You can open level select by listening to sounds 19, 65, 9 and 17 — then, while the final sound is highlighted, hitting the button you have designated as your “A” button and then hitting start.