I'll never get the power level debate of a Superman game. Like most comic media, it's a new version of the character. Which can allow for some wiggle room in terms of the character's capabilities. Superman in a video game can be powerful, and invulnerable to normal street thugs etc. But still take damage from advanced weapons, robots or mecha, other villains, you get it. It could be a middle ground power level for this particular incarnation of Superman. Strong and powerful, but not completely invulnerable.
Superman The Animated Series had the perfect power level for Superman. Look to that.