Bubble Shooter

Intro
The Bubble Shooter is a cheap water-based tower that costs $360 on Medium difficulty. It shoots 4 bubbles per second, but it only deals 1 damage every 4 bubbles. The bubbles move fast, but after half a second they slow down and then disappear. It has the range of a 0/2 Tack Shooter and can't see camo or pop lead.

Gear Grind ($350)
Shoots 6 bubbles per second.

Stronger Bubbles ($390)
It now takes 3 bubbles to deal 1 hit.

Machine Gun ($1560)
Shoots 10 bubbles per second.

Acid Bubbles ($2800)
Bubbles inflict poison (damage over time, 2 pops per second) for as long as the bloon leaks or gets popped, and the Bubble Shooter can now damage lead bloons. MOAB-classes can't be poisoned, and poison doesn't stack.

Bloon Slowing ($110)
Slows bloons that come in contact with this tower's bubbles, they move at 90% of their original speed for 2 seconds. MOAB-classes can't be slowed, and slowing doesn't stack.

Bloon Soak ($450)
Bubbles shot by this tower have a 20% chance to soak bloons. Soaked bloons move at 70% of their original speed for 3 seconds and lose their special traits when they're hit. This tower can now see camo bloons. MOAB-classes can't be soaked, and soaking only stacks with slowing.

Water Jets ($1920)
The Bubble Shooter now converts into the Stream Shooter that shoots strong water jets that pop bloons once per shot, still at the original bubble shooting speed.

Sea Dragon ($3500)
Sea Dragon Ability: For 8 seconds, shoots continuous blasts of blue fire that deal great damage to Ceramics and MOAB-classes. Cooldown: 24s