webgarb

Captcha Garb is yet a stylish puzzle like fun comment spam blocking plugin that block spam comment posted by automated bots.
The plug-in comes with 58 cool puzzle images and you even can upload yours direct from captcha garb admin page ! :).
Please comment you view about this plugin here <a href="http://webgarb.com/captcha-garb/" rel="nofollow ugc">Captcha Garb Page</a>.

Captcha Garb

Fun Captcha that your visitor also like to challange it.

Marcel Pol

<blockquote>
This plugin is essentially unmaintained. If you have it installed and configured, it will probably keep on working for a while.
You might want to take a look at a similar plugin <a href="https://wordpress.org/plugins/wp-shredderchess/" rel="ugc">WP-ShredderChess</a>.
This plugin uses the Yahoo YUI framework and an apparently unmaintained puzzle widget (last update in 2015). 
 It pulls in 600 KiB of JavaScript code, which is just a bit too much for such a simple widget.
</blockquote>
Widget that displays the chess puzzle from <a href="https://chesstempo.com/widgets.html" rel="nofollow ugc">chesstempo.com</a>.
<h4>Compatibility</h4>
This plugin is compatible with <a href="https://www.classicpress.net" rel="nofollow ugc">ClassicPress</a>.

WP Chesstempo

Widget that displays the chess puzzle from chesstempo.com.

Captcha Garb vs WP Chesstempo