I was going to play this with someone to see how it plays in two-player, but I think I can make some judgments without that. As far as the era goes, it's definitely a stretch. The screen is practically 1080p-ish with very small tiles. I use Godot as well, and if you want to have a smaller resolution but a bigger window, you need to turn the scaling up in the project settings. Should also remember to set textures to "nearest" for pixel art so it doesn't get blurry.
The game itself is largely unfinished in that you can still attack and move when you've lost (and I wasn't able to land a "finishing blow") and you can still defeat the other player when you've been defeated. Aside from that, adding some knockback at least would be a great start to giving the game a better feel with more feedback for the player.
Finally I think the controls could be reconsidered for the keyboard. Since you have WASD for player 1, you could do IJKL for player 2, and then you could have attack controls similar for both players. And not everyone has a tenkey keypad.
Otherwise, it's a decent start, and reminds me a little of Nidhogg, though not yet fully realized. Good work :)