“There are also coins to be earned by completing missions, which will apparently unlock Special Stages, new animation intros for each of the games, and most interestingly, “new content”. Sonic Origins will have a PlayStation 5 release, and currently has no exact launch date.”
It seems according to this the new animations aren’t even available from the start. You have to unlock them by doing special missions which give you in-game coins to use to unlock them…
“In the listing, we’ve learned that Sonic Origins will offer two different ways to play the classic 16-bit era Sonic games: Classic Mode, which is exactly how the games looked in 4:3 aspect ratio and played, utilizing a lives system, on the Sega Genesis, and Anniversary Mode, an updated take on the games, with a 16:9 widescreen mode and removal of any risk of game overs.”
And it seems like they have included the Hidden Palace Zone stage in Sonic the Hedgehog 2 which was originally removed late in development.
But apart from that, the only work they actually had to do on this project was Sonic 3 & Knuckles. All the other games were already remastered and released years ago. All they did was slap them in the project, next to Sonic 3 & Knuckles.