(RM2K3) I am making a Earthbound fan game and thinking about making a evil alternate route that’s basically just like the Undertale genocide, is this possible? (READ DESCRIPTION)

I was making a Earthbound fan game and thinking about making a evil route that’s basically just like the Undertale genocide route, you kill a certain amount of enemies in each area to progress and dialogue and gameplay changes and even some new boss fights, is something like this possible or do you think this would be to impossible/too difficult for RPG Maker 2003? If so any tips or anything to do this? Just a cool idea I had I would like to do if possible