Just as One Punch Man is a spoof of action anime, this game is that same spoof translated to having Saitama in a fighting game. It's a short game and has bugs but it's just a proof of concept. If you put Saitama in a fighting game, this is what you would get.

Got some sprites from spritedatabase.net for this.

Made the Saitama sprite and enemy death sprites on my own. Hope they satisfy. Enjoy!