A majority of the games M2 remade using stereoscopic 3d on the 3DS.

I'm not sure how transformative these games are, but with the upcoming assassination of the 3ds eshop means soon they will be mostly lost to time. There are 3 physical collections of these games that even include titles unavailable on backloggd, though only one released in the west.

The two Japanese exclusive collections, Sega 3D Fukkoku Archives and Sega 3D Fukkoku Archives 3, cost approximately... checks conversion rates... two of your kidneys and what remains of your liver. In other words it's important to keep some kind of list to remember them by and point out where they are accessible from at the current moment.

If you have more interest in these collections, here's the Wikipedia page discussing all three https://en.m.wikipedia.org/wiki/Sega_3D_Classics_Collection