Superman is almost invincible, with the obvious exception of Kryptonite, so how did you maintain tension without losing the massively powerful superhero feeling?
We balanced the game in two ways. First, you can't use your super powers all the time because you have stamina. Even in the comic books you see that Superman gets winded while he fights, and he needs to recharge his batteries. In the game that recharging happens automatically over time, or you can fly up closer to the sun and that speeds it up.