use Path::Class qw(file);
my @files;
find( \&wanted, $startdir );

sub wanted {
    my $file = file($File::Find::name);
    return unless -f $file->basename;
    push @files, $File::Find::name;
}

for (@files) {
    if (/\.zip/) {
        $zip->addFile($_)->desiredCompressionLevel(0);
    }
    else {
        $zip->addFile($_);
    }
}

$zip->writeToFileNamed('test.zip');