Turret guard war! Merge and idle game

Waves of monsters are ready to attack in surroundings.
Build your turrets and upgrade them constantly. Collaborate different turrets to bring magic effects!
Meanwhile, don't forget to upgrade your skills to strengthen power.
Don't feel upset when you can't defeat boss. Just calculate enough gems resource to enhance your trench.

Gameplay and features:
-Currently fashion gameplay. Tower defense, idle and merge.
-Don't take to much time or energy but need some casual time
-Collaborate skills and upgrade reasonably