Colony Siege

Colony Siege combines real-time strategy and tower defense. You build a colony, maze enemies into hazards and command defenses and mobile units to protect the Citadel. The campaign supports single-player and two-player online co-op.

Defend the colony

Colonies face attacks from two factions: the biomechanical Xenos swarm and the Riven, corrupted beings who were once human. Each faction behaves differently and calls for different tactics. The Citadel is your primary objective, but enemies can attack any part of the colony.

Build your defenses

Towers automatically form walls when placed near one another, and towers and barriers built close together generate a laser fence. Your mobile units can pass through these fences, while enemy movement is restricted. You can also use traps to slow, impale, burn or bombard enemies, and shockwaves and spring traps to launch them into cliffs, lava and other hazards.

Build and command mechs, tanks and other mobile ground units. You can also attack with satellite-powered strikes, long-range missiles, commander abilities, fighter sorties, and air, missile and orbital strikes against massed enemies.

Follow the campaign

The expansive, non-linear campaign spans dozens of missions, selected from a starmap with branching paths. You can press your advantage or replay earlier missions to earn extra cash. The entire campaign can be played alone or online with a friend, from the first mission to the last; you can combine forces or use different tactics.

Upgrade your forces

Completing primary and bonus mission objectives earns money to spend on persistent upgrades, new weapons, and different towers, traps, units and strikes. You can also unlock perks to strengthen your advantages or compensate for weaknesses.

Travel across varied environments

Missions take you to different planets, moons, space stations and enormous mobile space platforms.