In a far-off future... on a far-off world... you are called out of retirement to command the defense of terraformer installations attempting to convert the hostile environments of this alien planet.
Strange lifeforms and ancient machines are laying siege to sites all over the planet. Prove your command prowess one final time, and defend mankind's new hope.
With 4 elemental modules (fire, ice, iron, shock), build and fuse to protect essential human installations.

• Command 12 unique towers and even more elemental fusions to form the ultimate defense. Utilize fire modules to inflict lingering damage, ice modules to slow enemies to a crawl, shock modules to control crowds, and metal modules to inflict massive single target damage. Only the most carefully considered strategies will lead you to victory.
  
• Face off against 4 enemy varieties and 4 hulking boss enemy types. Slimy Reptyls and burrowing Insectoids sprint towards the terraformers, as ironclad Robots and lumbering Mutants clog your defenses with their slow speed and durability. Bosses also present their own unique challenges and surprises.
  
• Complete a campaign with a dozen missions, with unique maps and special Challenge Modifiers. Prepare for anything from bigger waves to towers getting frozen in time.
  
• Custom Scenario Mode allows you to create any mission you can imagine, from overpowered slaughter machines to impossibly challenging boss grinds.