This quest seems ambiguous. Surprising game as in rules, or game session? And surprising good, or surprising bad?
Surprise as it good? Because I encountered Marvel Heroic RPG before FATE, the whole idea of a fairly abstract system where descriptors of the PC's mattered as much if not more than stat blocks was a pretty novel concept, and frankly one that has so deeply ingrained itself into my game-brain that I'm constantly saying to myself, "That would be this [TV, movie, novel, or comic book character's] Distinction/Aspect."
I was so used to thinking of superheroes in terms of Champions with point-buy powers and loads of mechanics that the idea of not even having any sense of game balance was a real shock. But what really shocked me was how well it duplicated comic books, not just super heroes. Pacing, scenes, characters carting around the emotional baggage that is practically the hallmark of a Marvel story--all represented in gameplay.
Can I just say how surprised I was by the Firefly RPG, in terms of how poorly it was laid out? That's all I will need to say about that.