Посмотреть пример >>> ТУТ<<<

<script language="JavaScript">

// ---- Make array
function MakeArray( n){
this.length = n;
for (var i = 1; i <= n; i++) {
this[i] = 0
}
return this
}

// ----- poor man's random number
var d0 = new Date();
var r0 = d0.getSeconds();
function poor_rand(){
d1 = new Date();
r0 = (r0 * r0 + r0 + d1.getSeconds()) % 3721 ;
return r0 % width_n;
}

// ---- Parameters of game
var height_n = 8;
var width_n =5;

// ---- state of game
var enemy = new MakeArray( width_n); // enemy positions
var wtime; // wait time
var score; // points
var gameover; // in case of gameover set to true

// ----- Make the battlefield.
document.write( "<FORM NAME='fm1'>");
document.write( "<table style=\"border: 2 outset\"><tr><td bgcolor=\"#CCCCCC\" align=center>");
document.write( "<INPUT TYPE='text' NAME='message' value=\"Нажмите СТАРТ !\" readonly style=\"background-color:#000000; font-family: MS Sans Serif; font-size:2; font-weight: bold; color:lime\" SIZE=20>");
document.write( "<br>_________________");
document.write( "</FORM>");
document.write( "<FORM NAME='fm2'><TABLE>");
for( var i=0; i<height_n; i++){
document.write( "<TR>");
for( var j=0;j<width_n; j++){
document.write( "<TD><CENTER><INPUT TYPE='radio'></CENTER></TD>");
}
document.write( "</TR>");
}
document.write( "<TR>");
for( var j=0;j<width_n; j++){
document.write( "<TD><INPUT TYPE='button' VALUE=' ' style=\"background-image: url(\'arrow.gif\'); height:22\" onClick='fire(" + j + ")'></TD>");
}
document.write( "</TR>");
document.write( "</TABLE>");
document.write( "<INPUT TYPE='button' style=\"color:red\" VALUE='СТАРТ' onClick='game_start()'>");
document.write( "</td></tr></table>");
document.write( "</FORM>");
// ----- game main timer event
// ----- enemy come one step
function come(){
var n = poor_rand();
document.fm2.elements[ width_n * enemy[n+1] + n].checked = true;
enemy[n+1]++;
if( enemy[n+1] < height_n){
setTimeout("come()", wtime);
}else{
gameover = true;
document.fm1.message.value = "ИГРА ОКОНЧЕНА: " + score ;
}
}

// ----- Fire the n th beam
function fire( n){
if( gameover ) return;
for( var i=0; i<enemy[n+1]; i++){ // clear enemy
document.fm2.elements[ width_n * i + n].checked = false;
}
score += enemy[ n+1];
document.fm1.message.value = "ОЧКИ: " + score;
enemy[ n+1] = 0;
if( wtime > 100){ wtime -= 10};
}

// ---- initialize & start game
function game_start(){
for( var n=0; n<width_n; n++){
for( var i=0; i<enemy[n+1]; i++){
document.fm2.elements[ width_n * i + n].checked = false;
}
enemy[n+1] = 0;
}
wtime = 400;
score = 0;
gameover = false;
document.fm1.message.value = "ОЧКИ: " + score;
setTimeout("come()", wtime);
}

// -->
</script>