Garry's Mod - AND THUS BEGINS THE GREAT SALTENING OF OUR GENERATION

“suggesting any sonic character that isn't Eggman”

Shadow's not an option for this game though, he's currently an Assist Trophy. Maybe Smash 5.

Personally, however, I'd rather have Knuckles/Metal Sonic/Tails, even if, not gonna lie, I'd enjoy Shadow all the same.