You need to defend the crystal tower from waves of enemies for as long as possible. Destroying enemies earns resources that can be spent on various upgrades to make the tower stronger. The more waves you pass, the more dangerous and diverse your enemies will be. Remember that you will not be able to defend the tower indefinitely, but the players who are most successful in defending it will get to the top of the ranking of the best! Don't get upset after a defeat! The resources received during the battle can be spent on discovering new defensive or attacking abilities of the tower, leveling up existing improvements, hiring drone defenders, and many other useful features. Find your perfect strategy that will help you rise to the top of the ranking of the best players! Don't forget to expand and take care of your crystal farm, which is a great source of resources for improvements! The farm produces resources even when you are out of the game. Flexible progress system To mak...