Defend your core against escalating waves in a dark, sonar-lit arena. Your tower fires automatically; you choose the upgrades that keep it alive.

Build chain reactions, slow approaching enemies and time a Deep Pulse when the pressure rises. Enemies that reach your core stick to it—keep the growing mass inside the containment ring and push for a new personal best.

Experiment with six upgrade paths, learn your enemies in the Codex and track your run records.