Unique fusion of a top-down shooter and tower defense strategy. You are the invader! Use destructive weapons or lead your enemies into a maze of towers. Strategize in the build mode by carefully selecting various types of alien towers or throw yourself right into the heat of the battle.
As an alien invader, you control a versatile ship that seamlessly combines tower defense strategy and intense, arcade-style combat. You must carefully place and upgrade a variety of 7 specialized alien towers to defend your harvester from waves of incoming human forces. Simultaneously, you can freely pilot your ship around the battlefield, using its diverse arsenal of plasma, missile, laser, and bomb attacks to directly engage and destroy enemy units.
A key mechanic is your ability to shape and alter enemy paths. You can strategically demolish buildings and terrain, forcing enemies to take longer, more convoluted routes to your base. Enemies exhibit varied behaviors, with some capable of traversing gaps or flying over obstacles, requiring you to adapt your tower placements accordingly.
As you progress, you can unlock upgrades that enhance your tower's capabilities and your ship's firepower. This persistent progression system allows you to tailor your offensive and defensive options to meet the increasing challenge of each wave.
The game's environments are completely destructible, with nearly every structure and piece of terrain vulnerable to your attacks or the enemy's onslaught. The realistic physics simulation of collapsing buildings creates new obstacles and path changes that you can leverage to your advantage.
The game's campaign and survival modes support local cooperative play, allowing two players to coordinate their tower defense and combat roles. Effective teamwork is essential to managing the escalating waves of enemies.