Echo

Tap the screen to fire sonar pulses from your tank; waves expand outward, bounce off walls to reveal hidden enemies, and mark hit targets with echo indicators showing position and movement direction for 3 seconds. Hold to charge a super pulse with wider range and wall penetration. Hit 3+ enemies with one wave to trigger Chain Resonance for instant kills and +2 bonus points each. Survive the 90-second level timer and maximize your score.