Low damage tower
Will damage all balls in it's splash damage for the duration of the effect
Dark power is where it shines
The acid tower shoots acid that will splash out on impact, damaging all targets in the splash for the duration of the effect. It doesn't have much damage, but it's constant and can be useful in the middle where a lot of balls will fall through it's effect
The acid tower Dark Power gives it a chance to cause all balls damaged by the acid affect to take five times the normal damage. This effect will last until the ball is shrunk, making the dark power of the acid tower incredibly useful in later stages.