function win() { // create a function that runs when you win
    $('.win').show(); // show the message with JQuery
    $('.game').hide(); // hide the rest of the game
};

class Player { // create a player sprite class
    constructor(visibility) {
        this.visibility = visibility;
        setInterval(function() { // repeat this with a interval in between
            if (Math.abs(parseInt($('.player').css('left')) - parseInt($('.enemy').css('left'))) < parseInt($('.enemy').width()) && Math.abs(parseInt($('.player').css('top')) - $('.enemy').css('top')) < $('.enemy').height()) { // if the player if touching the enemy...
                game_over(); // then call the game_over function
            } else if (Math.abs(parseInt($('.player').css('top')) - parseInt($('.treasure').css('top'))) < parseInt($('.treasure').height())) { // otherwise if the player is touching the treasure...
                win(); // then call the win function
            };
        }, 1000); // do this each second
        $(document).on('keydown', ...

        }
    }
}