In addition to Sonic Colors Ultimate and unnamed new game that's coming out next year (which is presumed to be called "Sonic Rangers"), there's also a new collection game that's been announced:



By the looks of things, these may actually be the 2011/2013 Stealth/Taxman remakes. I say this, because aside from end of the trailer playing the same sound effect as the one heard in those versions, the games have also been shown to have widescreen display, along with Sonic's shoes having the white stripe on them while bouncing on a spring in Sonic 1 (which was not the case in the Genesis original, and was corrected in the 2013 remake).

In regards to Sonic 3 & Knuckles, however... While they did show an emulated version in the trailer, it's been hinted that this does not represent the final product. There was a Sega representative on Twitter who confirmed that it will have widescreen like the other three games. Plus, it should also be taken into account that Stealth and/or Taxman started on a proof-of-concept Sonic 3 & Knuckles remake about seven years ago, almost, which may have finally gotten a greenlight.

*YAWN* So far, I'm not impressed.

on the side, pokemon also jumping the open-world zelda bandwagon with a feudal-era prequel centered around arceus

https://diamondpearl.pokemon.com/en-us/
https://legends.pokemon.com/en-us/

its a wonder how sparkling zone got as far as it did to survive in a demo prototype build to be reviewed by the media before sonic team realized it as an epileptic mess and rather underdetailed for what should be expected from a 16-bit platform of those days

also there's data from 2/90 leftover in it
https://tcrf.net/images/1/13/Proto_Sonic_The_Hedgehog_Genesis_early_objects_anim.gif