Nova Defence

Nova Defence - a game on Android in which you have to save humanity from the alien invasion. Defend your earth from alien attack using a vast Arsenal of weapons. As well as improve a defensive strategy by upgrading your towers.
Features:

• 20 levels with a mass of defensive battles
• 20 specialized tower upgrades
• Over 50 different enemies
• features:
• 50 achievements
• Multiplayer with additional game modes