Quite possibly the easiest plugin to review ... because it just does what it says and allows you to play Chess within your Moodle course !However, it's worth noting that it is self-contained within a Block, so it's quite possible to play Chess while doing other things in Moodle such as Messaging, Chat, responding to Forums etc.  Obviously there is a limit to how many sites would want to install this plugin, but in schools, or social sites, it could certainly be well received :-)You can try ...

Very usable - and great fun !The graphics are very clear and the Block in easy to use.

To move the chess piece you have to use a mouse, which might be an accessibility issue for some users?  Not sure if the Block could implement a traditional chess notation system to allow moves to be input from the keyboard?  Although to be fair that is not the Moodle Block so much as the underlying code of the chess system.

I can't comment on the coding quality.  The documentation is brief, but sufficient.The Block is a very new release, so can't comment on how well maintained it might be in the future.We didn't notice any performance issues when the Block is added to a course.  Not sure if this might change if there were multiple players on the site/course at the same time?