Echo above sentiments: radio is completely wrong for this. You want checkboxes. Here's a snippet to play with. Sorry it's not adapted to your code above but I did it for fun. :) You can swap CGI for CGI::Pretty. The only difference is the output is better for human consumption with the pretty version.

use strict;
use warnings;
use CGI::Pretty;
my $cgi = CGI::Pretty->new();

print $cgi->header(), $cgi->start_html();

if ( my @selected = $cgi->param("catzez") ) {
    print $cgi->h1("You be checkin...");
    print $cgi->ul( $cgi->li( \@selected ) );
}
else
{
    print $cgi->h1("You chex sumdings, pleez.");
}

print
    $cgi->start_form(),
    $cgi->checkbox_group(
                         -name => "catzez",
                         -cols => 3,
                         -values => [ "Oh, hai!", "Oh, NOES!", "Oh, Pl
+eaze!",
                                      "I can haz PurlMunkz?",
                                      "Hacks. I gots dem.",
                                      "PERL. Yur doin it rong.",
                                      "Golf. Yer doin it... Pretty wel
+l akshully.",
                                      "Wherz mah buckit?", "They takes
+ mah buckit!" ],
                        ),
    $cgi->submit("Go, goez!");
    $cgi->end_form(),
    $cgi->end_html();
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