superman?

I'm generally not interested in the "who would win" type of discussions. However, I will give my opinion on this. Given the abilities Ralph displays, he is nowhere near Superman's capabilities. But very few superheroes (in DC) would be.

The suit had enough power to defeat normal bad guys mostly. The aliens found someone with courage and a pure heart to wear it, and then paired him with a tough, cynical guy to advise him.