Excellent pixel art and solid gameplay.
The addition of a training mode was extremely helpful to get used to the controls in a safe environment, and to take in the work done to the game's visuals. The most impressive part here is easily the spritework, the designs used are fantastic.
The gameplay, while solid, in my opinion could do with a few more tweaks. I personally found the character's movement speed to be a little too slow, though I feel this could be remedied with a dash movement to quickly close distances or create them.
While this was really the only issue I had with the gameplay, I do feel like there could have been a few animations for each player getting hit or knocked down, however I know that animations take time, so this is only a minor nitpick.
Really solid submission, well done!