- DEATHRAY COILS (4 upgrade points)
Replace the flags on each exit with deadly Tesla coils that zap incoming enemies.
Once the Deathray Coil upgrade has been bought, they will immediately replace the exit flags on any level you have or have yet to complete, in all three gameplay modes. Each coil works independently of the other, striking at a single enemy that enters its targeting range.
A coil will zap an enemy approaching the exit with a spark of red lightning, dealing it 150-300 true damage. The coils are charged and ready from the beginning but have a cooldown of 180 seconds, which means they should not be relied on to keep leaking enemies at bay, but they can catch an occasional enemy that leaks through.