Anomaly: Warzone Earth is a real-time strategy based on tower defense genre principles. However, instead of protecting your base from waves of enemies, in this game, you try to break into aliens’ facilities. 
The story is set in the near future when an alien spacecraft falls on Earth. As the head of an investigation team, you need to explore the anomalies happening around the parts of the ship and find out the information about the catastrophe. As the section of the spacecraft landed in several cities, game events take place around the world.  
The core gameplay is reversed tower defense mechanics. You have several armor units in the convoy; however, you can’t manage them directly. Instead, you need to set paths for them through the city streets and use different boosts to make your attack more effective and help the convoy survive. 
Anomaly: Warzone Earth is followed by Anomaly 2 that presents several new maps and mechanics including tower defense vs. tower offense multiplayer mode.