Monkey Bars

Monkey Bars cost 10 Green Paint, 2 Metal Pieces, $50, & 1 Dart Monkey. A monkey gets on a series of ten monkey bars dropping darts. Darts do 1 damage. The monkey attacks every second. He climbs back and forth on the bars.

Tier 1: Heavier Darts
Darts drop 2x faster and do 2x damage.
 * Cost: $100

Tier 2: 100Kilo Nails
Drops nails instead of darts, which are 100x heavier and do 10 damage.
 * Cost: 10 Metal Pieces, $1,000

Tier 3: Nailgun
Shoots nails instead of dropping them, going 10x faster.
 * Cost: 1 Gunpowder, 1 Metal Piece, $2,500

Tier 4: Nail Shooter Project MOAB
Shoots nails 2x faster, dealing 50 damage each.
 * Cost: 10 Gunpowder, 3 Metal Pieces, $5,000

Tier 1: Double Monkey
Two monkeys drop darts instead!
 * Cost: 1 Dart Monkey, $200

Tier 2: Quintuple Monkey
Now, five monkeys!
 * Cost: 1 Boomerang Monkey, $500

Tier 3: Dripping Hydrochlorine
Now, monkeys have hydrochloric acid dripping, so then they have Bloon Liquefier! Acid does 100 damage.
 * Cost: 1 4/x Glue Gunner, 1 Acidproof Paint, $6,500

Tier 4: Bloon Cyanide
Now, even cyanide can drip off of the bars! Cyanide does 100 damage.
 * Cost: 1 Poison Spider, 5 Poison Masks, $15,000
 * The Vortex Ability: A vortex of nails will spray around the tower, filling the whole track with flying nails.