Here are 2 different (unrelated) sticker sheets, but the thing they have in common is strange slogans.
The first sheet has 6 round stickers. They have "No room to manoeuvre", "Control Chaos", "See you on the f lip side!", "Try telling your brain it isn't real" (on both white and blue backgrounds" and "Chaos Theory". The Sonic graphic is very small on all but one sticker. What were these for?
The large sticker has a gray gradient background with "Segasonic the Hedgehog" written rightside up/upside-down around a ringed planet sort of shape that has Sonic's face in the center. The slogan here is small, in a blue & a black sort of oval shape down in the corner. It says "Space in yo Face" and "Check your head". Well...it does have a Sonic head there in the middle, you could check on that one, and it is vaguely space themed...so there's that? It's still kind of odd to just write that randomly on a sticker though.