I think a medieval style one-vs-one fighter is a great idea. This one needs some work unfortunately. I think the biggest single thing stopping it from feeling good to play is the fact that you need to hold the button to make all your animations play out. In other words, all actions can be instantly cancelled, even though you start dealing damage from your sword swing right away. So you can just run up to the other player, spam the sword button and win.
Aesthetically it has the core of being appealing, but it doesn't really match any specific retro look, with mixed sized sprites and large screen resolution.
I think you could have the bones of a good idea here, keep working on your skills and give it some love!