Look, we’re Cheat Code Central. Of course we’re all about this story. Cheat codes are few and far-between these days, but what series could be more infamous for its well-hidden cheats than Sonic the Hedgehog ? It makes perfect sense that the same sort of stuff has been tucked away in Sonic Mania , just waiting to be discovered by intrepid gamers. Sure enough, a list of codes has been discovered! And they showed up just after Sonic Mania Plus ‘ launch, too. We have the payload for your viewing pleasure.
Let’s go over what you need to do. First, you must enter Mania Mode. From there, you need to enter a Level Select code for each console. On the PlayStation 4, you hold the square button before you select the “No Save” option. On the Xbox One, you hold X while selecting “No Save.” On the Switch, you hold Y, then go to “No Save.” This takes you to the Level Select.
After that, you head to Sound Test. Here, you can enter a total of eight codes by playing the following sounds.
3 3 3 1 9 7 9 0 8 1 1 – Changes all animals into Squirrels.
4 1 2 6 – All Emeralds
1 9 9 2 1 1 2 4 – Infinite Continues
2 0 1 8 0 6 2 3 – Force Encore Mode
1 9 8 9 0 5 0 1 – Unknown
2 0 1 7 0 8 1 5 – Super Sonic Flight in normal levels (Don’t need to be Super to trigger it).
9 0 0 1 – Max Control For Sonic (Dropdash, Super Peel Out, Insta-Shield)
0 0 0 0 6 2 1 4 – Disable Super Music
Yeah, these codes are even styled after the originals, using the level select/sound test function as the cheat mechanism. Wild!
Source: Sonic Stadium