It was kinda of a platform sonic game, where if you lose, a full moon would appear and sonic would die (beheadead by a wolf or something like this) the game would have a creepy vibe and would pass between a castle (as i remember) and was kind of pixel graphics game, and i guess it came in a CD that i bought (not sure). I played it around 2002-2005. Can't remember the name of this one. I guess it has something to do with DOS/Windows 2000.
I guess the name of the CD was Digital something (it had a red dragon in the cover). Not sure if was in this one, but i'm trying my best to remember every detail.
It was a 2d game
edit: the name of the CD it's Digerati, it is a Brazilian group that developed these CD's, but still not sure if were they that developed this one, this is just something i remember from these days
"Horror" Sonic game in a castle
"Horror" Sonic game in a castle
Was it an official Sonic game or a fangame/bootleg title?
If the former, have you looked in this list:
https://www.mobygames.com/game-group/so ... t,0/so,1a/
If the former, have you looked in this list:
https://www.mobygames.com/game-group/so ... t,0/so,1a/
"Horror" Sonic game in a castle
Digerati has a homepage with their own games, but as you say they might have produced CD bundles of other developers games also.
https://www.digerati.games/games/
https://www.digerati.games/games/