• BLASTER
  Rapid-fire turret. Cheap, dependable, short range.
• LASER
  Sweeping beam that burns every creep along its line.
• MISSILE
  Homing missiles with splash damage. Long range.
• SHOCK
  Pulses that bog creeps down. Slows more targets as it grows.
• VORTEX
  Gravity well that drinks the debris of dead creeps and pours the energy into nearby towers. Double-tap to detonate.

Creeps follow the glowing track to your base. Build towers on the grid, upgrade them seven times, and bind them to a vortex to supercharge their shots. Kill creeps close to the base for bigger score multipliers.