We're making games here, doesn't mean they have to strictly be tied to comicbook multiverse canon. You can make a game where supes is strong enough to punch giant robots in the face and holds back his punches to beat dudes wearing power armor, make him fight parasite that's divided into thousands of copies, or metallo robots, or aliens from Apokolips, or kryptonians from Zod.

Or if the idea of him pulling his punches bothers you just have him infected with kryptonite poison and throught the game he has to "slowly recover himself and get stronger" (level up)

And have it set in Metropolis, Space, Apokolips, A 5th dimension weird level where Mxyzptlk is altering Metropolis to mess with you

Really the possibilities are limitless but I think all of you still think superman only fight goons that rob banks with a tiny gun?