Loop Defense: Acquisition Protocol

Loop Defense: Acquisition Protocol is a single-player sci-fi tower defense game built around custom enemy routes. Deploy across four unfamiliar planets, establish a base, and hold off waves of counterattacks while the Annihilation Device charges. As the campaign unfolds, new equipment lets you turn a handful of turrets into a full defensive outpost.

Design the enemy's approach and draw incoming forces through overlapping fields of fire. Build a winding defensive maze or concentrate your weapons around a narrow corridor. Experiment with layouts and find a plan that suits the battlefield.

Wall-breakers tear through your defenses, flying units close in from above, and carriers bring fresh reinforcements. A position that seemed secure can suddenly be under threat. Close the gaps, reposition your firepower, and prepare for the boss ahead.

Build your weapon lineup

Choose from 16 weapon modules. Hold enemy groups with Cold fire, pick off distant targets with Sniper turrets, or deploy specialized weapons on water maps. Combine bases and upgrade branches to put together a defense that fits your style.

Research unlocks new equipment and gives you more options for later missions. Choose a loadout before deployment, then add energy and production facilities to support your turrets and friendly units in battle.

Take on high-risk contracts

Wave contracts offer extra rewards for facing a harder assault. The added pressure can fund an earlier expansion or the weapon you need next. Decide how much risk your defense can handle.

Fight from the coastal defenses of Gray Harbor-7 to the waters and bridges of Double Day, then onward to Magforge and Glow Life. Advance across the star map and redesign your defenses for unfamiliar terrain and enemy forces.

The campaign also includes hidden missions, ship defense battles, and boss encounters. Complete acquisitions, unlock equipment, and move on to the next planet. Regular campaign missions offer four difficulty levels so you can begin at your own pace.

Endless Mode: Face escalating waves and see how long your favorite defense can hold.

Seeded expeditions: Plan a fresh defense on generated battlefields, try different lineups, or return to the same seed for another attempt.

Map editor: Create your own battlefield, arrange the terrain and enemy waves, then test the challenge yourself.

Available in English and Simplified Chinese, with a training mission and an in-game codex.