Add Checkboxes to Form

[Bestrafung]

I am trying to add checkboxes to the free agent signup form in the vbTournaments mod. I have created the extra field in the database table and a single selection works without issue. The problem I have is that when multiple checkboxes are selected only the last selection is saved to the database instead of all of the choices.

tmnt_newfreeagent template:

<form class="vbform block" action="teams.php?do=addfreeagent" method="post">
<div class="blockbody formcontrols">
	<div class="blockrow">
		<label for="game">Game</label>
		<div style="overflow:auto">
			<input type="checkbox" name="game[]" value="Aliens vs. Predator">Aliens vs. Predator<br />
			<input type="checkbox" name="game[]" value="Chivalry: Medeival Warfare">Chivalry: Medeival Warfare<br />
			<input type="checkbox" name="game[]" value="Counter-Strike: Global Offensive">Counter-Strike: Global Offensive<br />
			<input type="checkbox" name="game[]" value="Insurgency">Insurgency<br />
		</div>
		<p class="description">Please select the game(s) you play.</p>
	</div>
</div>
<div class="blockfoot actionbuttons">
	<div class="group">
		<input type="submit" class="button" value="{vb:rawphrase submit}" />
	</div>
</div>
</form>

teams.php:

PHP Code:

if ($_POST['do'] == 'insertfreeagent')
{
    if (!$tmntp['canjointeam'])
    {
        print_no_permission();
    }
    $count = $vbulletin->db->query_first("
        SELECT COUNT(*) AS countrows
        FROM " . TABLE_PREFIX . "tmnt_members
        WHERE userid = '".$vbulletin->userinfo['userid']."'
    ");
    if ($count['countrows'] != 0)
    {
        print_no_permission();
    }
    $userid = $vbulletin->userinfo['userid'];
    $available_day = $vbulletin->input->clean_gpc('p', 'available_day', TYPE_NOHTML);
    $available_time = $vbulletin->input->clean_gpc('p', 'available_time', TYPE_NOHTML);
    $reason = $vbulletin->input->clean_gpc('p', 'reason', TYPE_NOHTML);
    $description = $vbulletin->input->clean_gpc('p', 'description', TYPE_NOHTML);
    $game = $vbulletin->input->clean_gpc('p', 'game', TYPE_STR);
    if (!$description || !$available_day || !$available_time || !$reason)
    {
        $_REQUEST['do'] = 'addfreeagent';
        $incomplete_fields = true;
    }
    else
    {
        $ip = $_SERVER['REMOTE_ADDR'];
        $vbulletin->db->query_write("INSERT INTO " . TABLE_PREFIX . "tmnt_members
            (userid, teamid, time, ip, available_day, available_time, reason, description, game)
            VALUES (
                '".$vbulletin->db->escape_string($userid)."',
                '0',
                ".TIMENOW.", 
                '".$vbulletin->db->escape_string($ip)."',
                '".$vbulletin->db->escape_string($available_day)."',
                '".$vbulletin->db->escape_string($available_time)."',
                '".$vbulletin->db->escape_string($reason)."',
                '".$vbulletin->db->escape_string($description)."',
                '".$vbulletin->db->escape_string($game)."'
            )
        ");
        $vbulletin->url = "teams.php?do=freeagents";    
        eval(print_standard_redirect('redirect_insertfreeagent'));
    }
} 


I've tried both $vbulletin->input->clean_gpc('p', 'game', TYPE_STR) and $vbulletin->input->clean_gpc('p', 'game', TYPE_NOHTML) with no differences. I really don't understand the rest of this to proceed any further. If anyone could help me determine the issue I would greatly appreciate it.