Ultraboost (BTDB2)

BTD6

BTDB2

Sun Temple having a 10 stacked Ultraboost buff

“	Ultra-Overclocked Monkeys gain a small but permanent boost every time they are overclocked.	”
	~ BTDB2 description

Ultraboost is the 5th upgrade of Path 2 for the Engineer Monkey in Bloons TD Battles 2. It functions similarly to its BTD6 counterpart, with some minor differences. Aside from the reworked Cleansing Foam, the Ultraboost buffs wear off if the Ultraboost Engineer is sold, much like Permanent Brew. Also, each stack now counts for double the amount but half the maximum stacks for a single tower, allowing any Ultraboosted tower to gain full stacks faster.

The Ultraboost ability adds a +12.5% permanent "Ultra Charge" attack speed boost to the targeted tower (reduces attack cooldown by 8%). This special attack speed bonus can stack additively up to 5 times, and grants +66.7% attack speed to the target tower when maximized (40% attack cooldown reduction). The permanent boost and the Overclock boosting are different bonuses, meaning that they are not calculated together. Cooldown for the ability is 35 seconds, 10 seconds less compared to its predecessor.

When an Ultraboost is applied to the Monkey Village, the Monkey Village instead gains a 2.5% range buff per Ultraboost stack, up to +25% permanent range increase. For Banana Farms, they will produce +10% income per round per stack, up to +50% income.

Alongside the new ability, the Engineer's nailgun's pierce is increased by +15 (from 15 to 30), and the temporary Overclock buff from the Ultraboost lasts twice as long.

It costs $100,000, and is unlocked with the other Tier 5 Engineer Monkey upgrades for a one-off purchase of 1500.

Strategy

Summary

Ultraboost goes greatly with high-DPS towers such as the Super Monkey in the late game, which can make them shred and destroy BADs more quickly.

Tips

• Do not sell Ultraboost, as doing so removes ALL permanent buffs applied by the Ultraboost sold.
• You should try to get the Ultraboost as early as possible to boost a tower before a big rush of BADs.

Bugs

Current

• [1.0] Selling the Ultraboost Engineer Monkey removes all permanent Ultraboost buffs on the towers

Version History

Initial release (compared to BTD6 during Version 28.0)

• Selling the Ultraboost Engineer Monkey removes all permanent ultraboost buffs on the towers

1.1.0

• XP Cost reduced by 50% (35,000 XP → 17,500 XP)

1.5.0

• No longer requires 17,500 XP to unlock. Players who have unlocked this upgrade before the update will not receive a full refund, as well as unlock all Tier 5 Engineer Monkey upgrades.
• Ultraboost now costs 1500 for all Tier 5 Engineer Monkey upgrades instead of XP
• Affected by Cleansing Foam buffs

1.8.2

• Ultraboost costs less $120,000 → $100,000

???

• Ultraboost permastack effect is doubled but halved maxed number of stacks

4.0

• Ultraboost: The temporary Overclock buff now lasts twice as long (30s → 60s on a tier 5 tower)

“	We’re giving small boost to Ultraboost to help justify its incredibly high price tag.	”
	~ Ninja Kiwi

4.0.2

• Ultraboost: Boost now also affects sub-towers

4.1

• [Bugfix] Fixed Overclock boost not affecting sub-towers spawned after the boost was applied
• Overclock and Ultraboost buffs no longer increase 1+-x-x Engineer's sentry spawn rate

Gallery

5x Uboosted SChamp

Enough XP to unlock Ultraboost

Unlocked Ultraboost

Foam not being allowed to be targeted outside of initial range

Ultraboosted Sentry Champion with lots of Champion Sentries

Trivia

• In BTDB2, Ultraboost is the joint second-most expensive standalone upgrade in the game, alongside Legend of the Night, second to True Sun God at $200,000.