<!DOCTYPE html>
<html>
<head>
    <style>
    @keyframes play {
        from {
            background-position: right 0px bottom 0px;
        }
        to {
            background-position: right 250px bottom 250px;
        }
    }

    div {
        background-image: linear-gradient(blue, blue);
        background-size: 50px 50px;
        background-repeat: no-repeat;
        height: 300px;
        width: 300px;
        border: 1px solid black;
        animation: play 1000000s -10000s linear;
    }        
    </style>
</head>
<body>
    <div></div>
</body>
</html>