An UNUSED pin!
Is it modern? Modern...ish? This is a Sonic X-Treme pin, for the game that never came out. It would have been right before Sonic Adventure 1, had it appeared. It got pretty close to happening too, with magazine articles actual 'demo' like footage and other things. It's a subject you can certainly read up on. It even got to the point of a little tad of merchandise here and there...

And this is one of that. It's not really a prototype because, clearly, some of these pins did get made and it's in its final look of the release so it's not prototypical at all. It's a metal and enamel pin, with the game's logo in the 'Sonic' font and the more prickly 'extreme style' letters. It uses blue, black, white and purple. With the geometric shapes in the "Sonic" word, and the font-combo it really has an 80s-almost or 90s combination look. It's not Vaporwave but it looks like it might be on its way there with the color choice. It's a style and a path that Sonic games didn't go down.
This has to be a super rare pin, just because the game never happened. Also, for it to take all the way until 2019 to show up also says something about its rarity. This is an interesting item to see!