Really nice start to a brawler game, the sprites are fantastic and the atmosphere is well established. I love the animations for the attacks but it's a bit strange having them only play when the key is held down. I do like how the sprites get slightly bigger and smaller the closer they are to the camera, that's a nice touch.
I'm sure you know how you would take this further (player health, clear end goal etc) but this is a really solid start, nice one!