fans have spotted an interesting cameo from ' final boss, The End, in one of the final stages of , which raises some interesting questions about the timeline.
For the longest time, Sega has made a pretty clear distinction between the two Sonic timelines. There's the Classic timeline, which features the mute, chubby Sonic that we all know and love, and then there's the modern timeline with the more chatty and action-focused Hedgehog that we, uh, love despite his flaws.

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Aside from Classic Sonic teaming up with Modern Sonic for Generations and Forces, those two versions of Sonic are usually kept pretty separate from one another, a🐟s anyone hoping 🃏that Shadow would appear in a classic game will know. Well, Sonic Superstars includes an interesting cameo from a very recent character that unites the timelines a bit closer.
, Sonic Frontiers' final boss, The End, can actually be spotted in the background of the Egg Fortress stage, one of the final levels in Sonic Superstars. As you make your way through Egg Fortress' second stage, you'll occasionally be able to see out into space, where The End can be spotted glowing a slight purple in the background.
The End doesn't do all that much beyond glowing purple and looking a bit menacing (especially if you've struggled through the Final Horizon update), but it's an interesting easter egg that acts as a rare example of Classic Sonic and Modern Sonic sharing the same timeline. Although Sega has been pretty clear that it's not going to be bringing Shadow into the classic games any time soon, the fact that it's more openly referencing Modern Sonic could be a good sign that it's not an impossibility.
The appearance of The End in Sonic Superstars also suggests that he's actually been around for most of Sonic's classic adventures, even if the Blue Blur doesn't actually encounter him until much later in his life. If you want to put your tinfoil hats on, The End appearing here could indicate that Superstars is a sign that the classic series is inching closer to Sonic's modern era, but it's more likely just because Frontiers only just game out and it's a retroactive reference.
Whether Sega will keep including him in the background of other Sonic games and continue to hint at his eventual appearance in the series or if this is just a one-off joke that calls back to the most recent Sonic game isn't clear, but it's a nice touch that merges the two eras of Sonic closer together.