Besides the normal servers there is also a so-called test server, also called beta server. This server is not always available and only exists when it is needed.
The test server is generally used to test updates before they are uploaded to the other Server. Usually there is a short to long test phase in which the players can test the new functions to their heart's content. This way errors can be detected and things can be changed and adjusted before the update of the normal servers.
The time span of the test server's existence is flexible. It exists only as long as it is needed for testing. Therefore there is no entitlement to the accounts that are/have been played on the test server. When registering on the test server it should be clear that the accounts will not be playable forever and will disappear with the server itself!
Currently you can find the test server here: At the moment there is no test / beta server for monstersgames, as soon as there is something new it will be here :)