@WoW
Based on your suggestion, I can imagine two modes: a flight mode where Supes fly at high speeds; and a hover mode, where you can maneuver quickly (which can also works as walk mode when there is ground collision).
Now we're left with Supes method of attacking (while flying). At least for Iron Man, we can probably give him micro missiles to attack multiple targets (a sort of lock on mechanism, perhaps?). With Superman, we have heat vision (or icy breath). I don't know if those attacks lend well while Supes is flying at high speeds.
Maybe when flying, Superman's primary attack could be ramming (his fists) through enemies? So essentially, while flying, you are aiming for enemies straight on. (Hmm, that could work against a Godzilla-like enemy.)







