Hey. You know what? If we'll have to travel to November 12th, 1955 in the game... there will be THREE FREAKIN' MARTYS

(Heck, maybe that's what 'Double Visions' will be about, with the third Marty seeing himself DOUBLE...)
Now. I'm actually NOT sure if I would really want that. But the thought of it made me chuckle.
EDIT: I imagined this dialogue:
Marty from BttF2 drags Doc to his 1955 car after Doc passed out at the end of BttF2. Sees Marty and Doc from the game who have their business.
(sorry for the crudeness of the dialogue, it's just something that spontaneously appeared in my head)
Marty-BttF2: This is heavy! *releases Doc in shock and his body falls down with a bump*
Marty-Game: Oh, right, I was here at this moment. I forgot.
Marty-BttF2: All right, I'm glad Doc is here, this gives me some confidence, but... What the hell are we doing in this day AGAIN?
Marty-Game and Doc-Game look at each other. Marty-Game: Don't worry. I will rest for six months before all this shit happens. *Start to slowly walk away* Oh, and keep the letter ready. He'll have a recursion of his disbelief in Time Travel syndrome. And try to hide better in the fut... in the past, let's see how it works out, OK?
Marty-BttF2: Sure. Hey, will you at least help me drag Doc into his car? You're heavy Doc, and nothing has happened to Earth's gravitational pull yet!
Doc-Game and Marty-Game look at each other again. Doc-Game: Well it's not like we can make it any more worse. *looks at Marty-Game* And I don't want you to drop me several more times again.