Sign Posts, Star Post, And Goal Rings Are Literal
So in Sonic Frontiers Sonic straight up mentions the existence of Sign Posts and Goal Rings confirming they are an actual thing and not just a gameplay mechanic. This is further backed up by the fact you can fish one up in Big Fishing sections with a description further confirming this. They also depict Classic Eggman confirming again Classic Sonic is Modern Sonic's past self.
Separately the Star Post can be fished up with a description that tells us to can teleport someone out off danger as they fall down into a pit if you've previously touched one. This also may mean extra lives aren't literal in the Sonic world. Written by Eris











