If you've beaten Sonic Superstars already and are looking for something else to do, don't play something else! Do what this enterprising Sonic fan has done, and fiddle with the game until you find something interesting. And something interesting they did find - a Debug Menu that allows you to select a starting stage and sound test.
The discovery comes from YouTuber 'Kilo', who outlines the steps in the video below. Please bear in mind that, if you've not completed Sonic Superstars just yet and don't want to be spoiled, go away and come back when you've beaten it because there's a few minor details in the video that could ruin things for you.
With that said, here's the video!
To pull off the cheat, you will need to have beaten Story Mode already and be at the main menu. Then, press the following button combination (relative to an Xbox controller - so we assume the relevant keys on a PlayStation or Switch controller will also work, but this has not yet been tested);
X, X, Y, Y, X, X, X, X
You'll then enter a very basic and boxy menu that leaves absolutely nothing to the imagination. And from there, you can select a starting stage (which is kind of useless if you've already beaten the game) or play around with the sound test (which is a bit less useless since the Sonic Superstars OST hasn't hit Spotify yet). Hey, at least the menu's blue!
Let us know what you think in the comments below (and be careful, the comments may also be a little spoilerific!).