html {
    overflow: hidden;
    height: 100%;
    background: #191919;
    width: 100%;
}

#canvas {
    background: url('https://marclopezavila.github.io/planet-defense-game/img/space.jpg') no-repeat;
    width: 100%;
    height: 100%;
    background-size: cover;
}

#canvas.playing {
    cursor: url('https://marclopezavila.github.io/planet-defense-game/img/aim_red.png') 17.5 17.5,auto !important;
}