I am thinking about a game that pays homage to the comics that I loved as a kid. While I loved the DC comics, it was the Marvel universe that really drew me in. With that being said, I propose for my campaign:
"With great power comes great responsibility."
"Mayhem in the Mighty Marvel Manner!"
The first statement should make the players realize that there are always consequences to their actions, while the second lets them know that they will be dealing with threats in locations that are well established in the Marvel Comics universe of the 1970s and 1980s. Threats can come from beneath the Earth (Mole Man in Fantastic Four #1), from space (the Kree, Skrulls, Shi'ar, Celestials, etc), or from humanity itself (Eternals, Deviants, Mutants, Atlanteans, Maggia, Roxxon, etc.).
The statements don't definitively say that those things will happen, but they let the players know that they COULD. I think this will also help to guide their thinking in how they would choose to interact with the Marvel Universe if they were given the opportunity. This is just my thinking aloud about it, but it has really helped me to get my own creativity moving to create threats and adventure opportunities that the players will enjoy.
Any thoughts on this?