<h1style="text-align:center">Space Invaders destroyed this page!</h1>
<h2>Take revenge on them!</h2>
<pclass="center"><br>Use <spanclass="label label-danger">Space</span> to shoot and <spanclass="label label-danger">←</span> <spanclass="label label-danger">→</span> to move!   <buttonclass="btn btn-default btn-xs"id="restart">Restart</button> or <buttonclass="btn btn-default btn-xs"onclick="location.href='javascript:history.back()'"type="button">