What is the Global Defense: Zombie War game, how does it work?

According to the introduction of Cat Studio, Global Defense: Zombie War is a Strategy game on the Android platform. There is currently a 1.6.1 version released on Jan 04, 2020, you can see the details below.

Do you like shooting zombies? If you do, you will like this TD game!
The end day is coming! This is the last war between human and zombies.
Cities are ruined, and human are forced to hide in their last shelters. Your mission is to build turrets along the road to protect human while kill zombies!

Features:
- Stunning visual effects, high-resolution images and amazing sound effects.
- Different from other TD games, the zombies always appear in groups in this game! You will enjoy the pleasure to kill hundreds of zombies at an instant!
- Kill zombies in over 100 cities all around the world. Each city has a unique view, and the game will offer you endless fun!
- 9 different types of turrets.
- A wide variety of zombies.
- 2 defense modes and 3 difficulty levels.
- 3 special skills: the Space Laser, the Shockwave Bomb and the B2 bomber.
- The truly original weapons in the modern war and some sci-fi elements.
- The tower upgrading system.
- Chance to win random items after destroying zombies.
- The military ranking system and 27 medals waiting for you to achieve.

What's new in version 1.6.1 Fix bugs