#!/usr/bin/perl
use strict;
use Term::ReadKey;
ReadMode 'cbreak';

# init some stuff
$,=$/;
$/=++$b+$b;
$=='8';
$b=$=x28;
$*=$=x2;
@!=(qw(4 _ " a 1 1 0 0 ));
$![7]=`clear`;

# prepare an important string...
push(@!,split shift(@!),q 7$=W8W$=8$b eq "j"8W$=8$=W8 $b eq
"l"8W$=8W!8($b eq"k"&&$_!~/!/)a#W$=8#$=W8$=W#8W$=#8#!8##a\*8
$=8p$=8$=p8$=q8q$=8p(#.{59})$=8$=$1q8#q(.{60})$=8#$=$1
pap(.{60})!8$![0]++;"\*$1$="8q(.{60})!8$![0]++;
"\*$1$="8(t.*)!8$b=(length$1)-61;
substr($1,0,$b )."!". substr($1,$b+1).$=4x"gs'"x"c"es'"c"z"gs if'
.shift"z"l"just another perl hacker"l4'SpaceInvaders'.($=x12)
.'domm@zsi.at j=left k=fire l=right'_'#'x58_("$*p$*"x11).
  $=x3_$*.("$*$*q"x11).$=_("p$*$*"x11).$=x3_($=x3).("$*$*q"x11)_
1_$b.$=."W$b"_'#'x 587);

# generate board and regex subs
j(split shift@!,pop@!);
a(split shift@!,pop@!);
push(@!,split shift@!,pop@!);
$_=$a;
map{s/\n//g}@!;
map{s/  //g}@!;

# start main loop
&p;

# subs
sub END{
  ReadMode 'normal'
}

# init board
sub j {
  $_=shift;
  $a.=m/^1/?("#$b$=$=$b#$,"x12):"#".eval( )."#$,";
  @_&&j(@_)
}

# generate routines
sub a {
  eval"sub'".pop().'{eval\'s/\'.(shift).\'/\'.(shift).\'/'.pop().';@_&&'.pop().'(@_)}';
  @_&&a(@_)
}

# main loop
sub p{
  $b=ReadKey -1;
  $![1]%3==0&&x(split$=,$![6]);
  z(split$=,$![4]);
  x(split$=,$![5]);
  c(split$=,$![7]);
  $![1]++;
  select (@-,@-,@-,0.05);
  ($![2]=$_)=~s/$=/ /g;
  /pW|Wq/&&h('Game over');
  $_!~/p|q/&&h('You saved our planet. Yeah');
  print $![3],$![2];
  &p
}

# print end message
sub h {
  print $![3],shift,"You killed $![0] space invaders",$,;
  exit
}

##</code><code>##

#!/usr/bin/perl
use strict;
use Term::ReadKey;
ReadMode 'cbreak';

##</code><code>##

# init some stuff
$,=$/;
$/=++$b+$b;
$=='8';
$b=$=x28;
$*=$=x2;
@!=(qw(4 _ " a 1 1 0 0 ));
$![7]=`clear`;

##</code><code>##

# prepare an important string...
push(@!,split shift(@!),
q 7$=W8W$=8$b eq "j"8W$=8$=W8 $b eq
"l"8W$=8W!8($b eq"k"&&$_!~/!/)a#W$=8#$=W8$=W#8W$=#8#!8##a\*8
$=8p$=8$=p8$=q8q$=8p(#.{59})$=8$=$1q8#q(.{60})$=8#$=$1
pap(.{60})!8$![0]++;"\*$1$="8q(.{60})!8$![0]++;
"\*$1$="8(t.*)!8$b=(length$1)-61;
substr($1,0,$b )."!". substr($1,$b+1).$=4x"gs'"x"c"es'"c"z"gs if'
.shift"z"l"just another perl hacker"l4'SpaceInvaders'.($=x12)
.'domm@zsi.at j=left k=fire l=right'_'#'x58_("$*p$*"x11).
  $=x3_$*.("$*$*q"x11).$=_("p$*$*"x11).$=x3_($=x3).("$*$*q"x11)_
1_$b.$=."W$b"_'#'x 587);

##</code><code>##

push(@! split(4,"$=W...58"));

##</code><code>##

$=W8W$=8$b eq "j"8W$=8$=W8 $b eq"l"8W$=8W!8($b eq"k"&&$_!~/!/)a#W$=8#$=W8$=W#8W$=#8#!8##a\*8$=8p$=8$=p8$=q8q$=8p(#.{59})$=8$=$1q8#q(.{60})$=8#$=$1pap(.{60})!8$![0]++;"\*$1$="8q(.{60})!8$![0]++;"\*$1$="8(t.*)!8$b=(length$1)-61;substr($1,0,$b )."!". substr($1,$b+1).$=
<br>
x"gs'"x"c"es'"c"z"gs if'.shift"z"l"just another perl hacker"l
<br>
'SpaceInvaders'.($=x12).'domm@zsi.at j=left k=fire l=right'_'#'x58_("$*p$*"x11).  $=x3_$*.("$*$*q"x11).$=_("p$*$*"x11).$=x3_($=x3).("$*$*q"x11)_1_$b.$=."W$b"_'#'x 58

##</code><code>##

# generate board and regex subs
j(split shift@!,pop@!);
a(split shift@!,pop@!);
push(@!,split shift@!,pop@!);
$_=$a;
map{s/\n//g}@!;
map{s/  //g}@!;

# start main loop
&p;

##</code><code>##

(
 'SpaceInvaders'.($=x12).'domm@zsi.at j=left k=fire l=right',
 '#'x58,
 ("$*p$*"x11).$=x3_$*.("$*$*q"x11).$=,
 ("p$*$*"x11).$=x3_($=x3).("$*$*q"x11),
 1,
 $b.$=."W$b",
 '#'x 58,
)

##</code><code>##

(
 'SpaceInvaders'.('8'x12).'domm@zsi.at j=left k=fire l=right',
 '#'x58,
 ("88p88"x11).'8'x3,
 '88'.("8888q"x11).'8',
 ("p8888"x11).'8'x3
 ('8'x3).("8888q"x11),
 1,
 '88888888888888888888888888888'.'8'."W88888888888888888888888888888",
 '#'x 58,
)

##</code><code>##

# init map
sub j {
  $_=shift;
  $a.=m/^1/?("#$b$=$=$b#$,"x12):"#".eval( )."#$,";
  @_&&j(@_)
}

##</code><code>##

(x, gs', x, c, es', c, z, gs if'.shift, z, l , just another perl hacker ,l)

##</code><code>##

sub a {
  eval"sub'".pop().'{eval\'s/\'.(shift).\'/\'.(shift).\'/'.pop().';@_&&'.pop().'(@_)}';
  @_&&a(@_)
}

##</code><code>##

(
$=W8W$=8$b eq "j"8W$=8$=W8 $b eq"l"8W$=8W!8($b eq"k"&&$_!~/!/)
#W$=8#$=W8$=W#8W$=#8#!8##
\*8$=8p$=8$=p8$=q8q$=8p(#.{59})$=8$=$1q8#q(.{60})$=8#$=$1p
p(.{60})!8$![0]++;"\*$1$="8q(.{60})!8$![0]++;"\*$1$="8(t.*)!8$b=(length$1)-61;substr($1,0,$b )."!". substr($1,$b+1).$=
)

##</code><code>##

$_=$a;
map{s/\n//g}@!;
map{s/  //g}@!;

##</code><code>##

sub p{
  $b=ReadKey -1;
  $![1]%3==0&&x(split$=,$![6]);
  z(split$=,$![4]);
  x(split$=,$![5]);
  c(split$=,$![7]);
  $![1]++;
  select (@-,@-,@-,0.05);
  ($![2]=$_)=~s/$=/ /g;
  /pW|Wq/&&h('Game over');
  $_!~/p|q/&&h('You saved our planet. Yeah');
  print $![3],$![2];
  &p
}

##</code><code>##

$![1]</code< (this is where we store the number of moves) and 3 is zero (i.e. every three moves), call <i>x</i>. <i>x</i> is one of the autogenerated subs that does some substitution on $_. It substitutes the first value passed to it with the second, until there are no values left.<br>
What gets passed to <i>x</i> is <code>$![6]
##</code><code>##

\*           $=
p$=          $=p
$=q          q$=
p(#.{59})$=  $=$1q
q(.{60})$=   #$=$1p

##</code><code>##

  z(split$=,$![4]);
  x(split$=,$![5]);
  c(split$=,$![7]);

##</code><code>##

sub h {
  print $![3],shift,"You killed $![0] space invaders",$,;
  exit
}

##</code><code>##

sub END{
  ReadMode 'normal'
}