Like others have said, definitely gives off an old street fighter style game. I'm not sure if this is just a browser play thing but a lot of time my punches and kick inputs were just not registering. I would be right up on the opponent and not able to hit them, yet they could hit me.
Like the invincibility build up. If things pick up steam, I'd work on the enemy hit box BUT this could also just be a browser issue. (or a player issue)