Super Hero Racers!
In many respects, this is a traditional racing game. Except that instead of driving cars, you’re controlling super heroes. Each super hero has a different mode of transportation - some fly, some run, some use gadgets or silver surfboards or whatever other ridiculous things spandex heroes use.
While racing, there are two complementary goals: win the race and maintain a high public perception. Your public perception is impacted by things you do during the race: if you do a trick, the citizens applaud. If you take a longer route to save a distressed reporter, the citizens applaud. If, in your haste, you accidentally run into a building and knock it down, the citizens are angered. You gain and lose points per these actions and you gain some fixed number of points for placing in the race, and the person with the most points wins. Think Excite Trucks (aside: that’s a fantastic game).
Of course, every hero utilizes super powers throughout the race. Little gems on the track give you “super energy” which you can then spend to use your heroes powers. Each hero would have one or two unique powers - carefully balanced to make sure that no hero is ridiculous overpowered.
Race tracks would vary. There could be evil fortresses or cities or abandoned laboratories or dense jungles. It leaves about as much room as Mario Kart in this respect.
I still have one open question: should the races be confined to an essentially 2D track or should they be fully navigable 3D environments? I think full 3D environments leave a lot of room for creativity here - some heroes gain advantages depending on their mode of transportation - but it’s also harder to balance and harder to move the race in the right direction. A 2D track is more traditional and more controlled and eliminates unfair advantage, but it removes some possibilities.