It seems like a real game yet the gun is weird for Sonic, yet Sonic Team has been trying to make Sonic do new things (Sonic Heroes was to see if the new things would go overwell, mainly the team work theme). I can see a game with Shadow, he has a large story behind him and he is on the edge of good an evil... so in the video it says you do decide if he is good or evil, it would be a cool way to play out the game. I'm sure Rouge will make an apperence... yet she might not be playable she is sorta like Shadow's guide and his best friends, and I can also see Eggman and maybe... maybe Omega. There will prolly be a lot of Maria, Gerald, and the goverment talk in this too because they play a big role in Shadow's life.
If it isin't exacally confirmed then we will see in time... I always thought of a game starring Shadow to be possable. And if they add the Chaos Emeralds in this then I suppose Super Shadow will make his grand reapperence (Yes Super Shadpw, not Hyper Shadow... long story, only way to achive a Hyper form is through the Super Emeralds and they haven't been seen since Sonic 3 and Knuckles... just saying because some people call him Hyper Shadow, but who really knows *Shrugs*). Yet the gun still seems odd but its something that can easly grow on me... because its just like Omega or Gamma, stop every few seconds to shoot things... yet with the speed of Shadow. Well if they make it sounds like a buy for me.