If MKXP isn't working on Windows 10 there's not a lot I can offer you sadly, I don't know of any fixes. Maybe compatibility mode for Windows 7 if you haven't tried that.
That's okay, either way when I played the game nearly a year ago, it was absolutely amazing and I commend you for making such a great game for what must have been very little money.
I fixed it by updating Windows to the newest version. Apparently it doesnt prompt you for it for whatever reason. I have a question though now that im doing the Rodriguez route, what do the moves "You're Mine" and "Do Something" do? I see states that are obviously of your own creation but its not clear what they do and the wiki is of little help.