Hearty congrats to Telltale for another entertaining and engaging game! You folks are setting a pretty high bar for interactive fiction, which is nothing short of what is expected of your staff.
While the ending to OUTATIME effectively ratchets up some hype for the next season, I was fully expecting what (to me) would have been a more interesting cliffhanger for BTTF continuity. That being: Artie marries Trixie, who would NOT really be Sylvia. This would (of course) lead to some change in the McFly family gene pool, as evidenced by "Michael J. Fox" Marty cross-dissolving into the first movie's abandoned "Eric Stoltz" Marty.
This could have led to some interesting situations in the second season as Marty and Doc embarked on another time-travel quest to reclaim Marty's true identity. "Eric Stoltz" Marty could have had some different personality traits that would grow more defined as the story progressed, to the point where he changes his mind about reverting... potentially risking one of those universe-destroying paradoxes. Think about it: so far the BTTF stories have basically been about changing other peoples' destinies. It might have been an interesting approach to have something themed on altering one's own identity.