The Final Flash Masterpiece
Released by Ninja Kiwi in late 2009, Bloons Tower Defense 4 represents the pinnacle of Flash-based tower defense gaming. As the final major Flash entry before the series evolved to modern engines, BTD4 introduced revolutionary features including new towers, expanded upgrade paths, and challenging game modes that pushed players' strategic skills to their limits.
BTD4 also spawned an Expansion version that added the Dartling Gun and Spike Factory towers, plus the unique Deflation Mode where you start with $50,000 but earn no additional income. This guide provides expert-level strategies for conquering BTD4's most demanding difficulties and challenge levels.
Why BTD4 Remains Challenging
BTD4's limited tower pool and extended round counts (75 rounds on Hard) demand efficient economy management, precise tower knowledge, and adaptive tactics for each track and challenge mode.
Game Modes and Difficulties
BTD4 offers three core difficulty settings plus specialized challenge modes that test different aspects of strategic mastery.
Easy Mode
- 200 lives
- 50 rounds
- Standard tower costs
- Forgiving economy
Medium Mode
- 150 lives
- 60 rounds
- Slightly higher costs
- More bloon waves
Hard Mode
- 100 lives only
- 75 rounds
- Increased tower prices
- Earlier camo/lead bloons
Special Challenge Modes
Apopalypse Mode
Unlocked at rank 31 - continuous waves with no breaks
Strategy: Build economy early, constant pressure defense
MOAB Challenge
Features massive MOAB blimps in overwhelming numbers
Strategy: Multiple MOAB Maulers, Monkey Storm ability
Lollipop Challenge
Restricts available towers and upgrade options
Strategy: Ring of Fire, Monkey Apprentices, early Beacon
Deflation Mode
$50,000 starting cash, no additional income
Strategy: Pre-plan entire defense, Spike Factories at exits
Hard Mode Key Differences
Resource Management
- • Banana Farms become critical early investment
- • Extended 75 rounds require long-term planning
- • Higher tower costs demand efficiency
Bloon Threats
- • Camo bloons appear earlier (need detection)
- • Lead bloons mixed into regular rounds
- • More MOABs and BFBs in late game
Understanding Towers and Upgrades
BTD4 features 16 main towers, each with unique upgrade paths and strategic applications. Mastering their synergies and knowing when to invest in each tower is crucial for expert-level play.
Essential Tower Knowledge
Understanding bloon immunities is critical:
- • Black: Immune to explosives
- • White: Immune to freezing
- • Zebra: Both immunities combined
- • Lead: Immune to sharp projectiles
- • Camo: Requires detection to target
- • Ceramic: Takes multiple hits
Essential Towers for Expert Play
Banana Farm - Economic Foundation
Key Upgrades: Banana Plantation → Republic → Research Facility
Expert Tip: Build 2-3 farms by Round 15. Early investment yields exponential returns for late-game MOAB Maulers and Sun God upgrades.
Tack Shooter - Ring of Fire Powerhouse
Key Upgrades: Faster Shooting → Blade Shooter → Ring of Fire
Expert Tip: Position at corners for multi-path hits. Ring of Fire melts leads, ceramics, and black bloons - one of the best mid-game upgrades.
Bomb Tower - MOAB Specialist
Key Upgrades: Bigger Bombs → Missile Launcher → MOAB Mauler
Expert Tip: Essential for leads and MOABs. MOAB Mauler deals 10× damage to blimps. Build multiple by Round 44 for MOAB survival.
Monkey Beacon - Support Master
Key Upgrades: Wider Influence → Jungle Drums → Sonar Beacon + Monkey Storm
Expert Tip: Always build near tower clusters. Sonar reveals camos, Monkey Storm clears entire screen - perfect panic button.
Monkey Apprentice - Cost-Effective Powerhouse
Key Upgrades: Intense Magic → Fireball → Tempest Tornado
Expert Tip: Tornado pushes bloons backward while dealing area damage. Many experts prefer multiple Apprentices over expensive Super Monkeys.
Super Monkey - Late Game Destroyer
Key Upgrades: Super Range → Laser Vision → Plasma Vision → Sun God
Expert Tip: Only invest after strong economy. Sun God obliterates MOABs and BFBs. Sell Banana Farms around Round 50 to afford this upgrade.
Expansion Towers
Dartling Gun
Fires darts along mouse pointer with laser and rocket upgrades
Use: Flexible crowd control - reposition by moving mouse
Spike Factory
Automatically lays road spikes and spiked balls
Use: Perfect near exits to catch leaks, essential in Deflation Mode
Expert Strategies for Hard Modes and Challenges
Conquering BTD4's toughest challenges requires methodical progression through three distinct phases, each demanding specific strategies and tower priorities.
Early Game Setup (Rounds 1-20)
Cost-Effective Foundation
- • Start with Dart Monkey + Piercing Darts
- • Add Tack Shooter at corners for wide coverage
- • Build 2-3 cheap towers before expensive upgrades
- • One Dart + one Tack can clear first 4 rounds on Hard
Economic Investment
- • Place first Banana Farm by Round 10-12
- • Upgrade to Banana Plantation immediately
- • Build 2-3 Farms by Round 20
- • Prioritize experience on Tack/Bomb/Super Monkey
Critical Early Game Mistakes to Avoid
Don't overspend on road items (spikes/glue) early - money is scarce. Avoid clustering towers at entrance - spread coverage for backup defense.
Mid Game: Lead, Camo & Ceramics (Rounds 21-45)
Essential Preparations
Lead & Camo Detection
- • Bomb Tower by Round 20 (first lead ~ Round 23)
- • Upgrade to Missile Launcher quickly
- • Monkey Beacon with Sonar by Round 24
- • Alternative: Monkey Ace Spy Plane
Defense Distribution
- • Spread towers along track (not just entrance)
- • Backup Dart Monkeys or Spike Factory near exit
- • Use Mortars for long-range, line-of-sight-free support
- • Position Ice/Glue away from sharp towers
Ring of Fire Timing
Around Round 30, upgrade Tack Shooters to Blade Shooter. By Round 40, convert to Ring of Fire - this creates an impenetrable wall that melts leads, blacks, and ceramics.
Pro Tip: Place Ring of Fire at choke points where bloons pass multiple times for maximum efficiency.
Late Game: MOAB & BFB Warfare (Rounds 46-75)
MOAB Preparation Strategy
First MOAB appears on Round 46 (Hard Mode). Preparation is everything:
MOAB Maulers & Support
- • Upgrade 3+ Bomb Towers to MOAB Mauler by R44-45
- • Position near Monkey Beacon for attack speed buff
- • Add Boomerang Glaive Throwers for cleanup
- • Keep money ready for Monkey Storm ability
Alternative: Apprentice Spam
- • Multiple Monkey Apprentices with Tempest Tornado
- • Cheaper than Super Monkeys, push bloons backward
- • Only invest in Sun God with strong economy
- • Upgrade sequentially around Rounds 50-55
Advanced Late Game Tactics
- • Sell and Rebuy: Sell Banana Farms and cheap towers in last 10 rounds for upgrades
- • Emergency Spikes: Drop road spikes near exit if MOAB rush threatens
- • Pineapple Timing: Use expansion Pineapple bombs on lead/ceramic clusters
- • Dartling Micro: Continuously adjust mouse aim for dense bloon clusters
Track-Specific & Challenge Tips
Single-Path Tracks
- • Spike-O-Pult near start for straight-line coverage
- • Bomb Tower at center, Tack Shooters at corners
- • Stagger tower placement: early, mid, late coverage
- • Ring of Fire upgrade before Round 40
Multi-Path Advanced Tracks
- • Mortars and Monkey Aces reach multiple lanes
- • Centralize towers at intersections
- • Use Ice/Glue to stall one path while handling other
- • Position for maximum dual-lane coverage
Challenge Mode Strategies
Lollipop Challenge
Limited towers: rely on Ring of Fire + Monkey Apprentices, early Beacon for camo
MOAB Challenge
Multiple MOAB Maulers positioned for repeated shots, Monkey Storm for emergencies
Apopalypse Mode
Continuous waves: multiple Banana Farms early, Whirlwind Apprentices for constant pushback
Deflation Mode
$50K no income: plan entire defense, MOAB Maulers + Ring of Fire + Sun God + Spike Factories
Advanced Combos and Synergies
Master-level BTD4 play relies on understanding powerful tower combinations that multiply effectiveness beyond individual tower capabilities.
Ring of Fire + Glue/Whirlwind
Combining Ring of Fire with Glue Gunner (Corrosive) or Monkey Apprentice (Whirlwind) creates devastating efficiency.
Synergy: Glue/tornado slows or sends bloons back, allowing Ring to burn them multiple times. Devastates ceramic and rainbow waves.
MOAB Maulers + Monkey Beacon
Cluster of MOAB Mauler Bomb Towers under Monkey Beacon's Jungle Drums aura produces rapid, high-damage bursts.
Enhancement: Add Sonar Beacon upgrade to handle camo MOABs in challenge rounds. Perfect for MOAB Challenge mode.
Dartling Gun + Spike Factory
Dartling Gun continuously chips bloon clusters while Spike Factory lays defensive coverage at exits.
Best Use: Particularly strong on maps with long straight lanes. Micro-adjust Dartling aim for maximum efficiency.
Mortar + Ice Synergy
Mortar shells strip camo layers and damage bloons while Ice Tower freezes and slows them for follow-up attacks.
Finishing Move: Bombs or Ring of Fire positioned near choke points finish frozen clusters for massive area clearance.
Master-Level Combo Principles
Timing Synergies
- • Slow/stall towers create opportunities
- • Area damage towers capitalize on clustering
- • Support towers multiply main damage dealers
Resource Efficiency
- • Combos > individual expensive towers
- • Beacon buffs affect multiple towers
- • Strategic positioning maximizes synergies
Master the Final Flash Challenge
Bloons Tower Defense 4 remains one of the series' most demanding entries due to its limited tower pool, extended round counts, and challenging game modes. True mastery requires efficient Banana Farm economy management, deep knowledge of tower strengths and immunities, and the ability to adapt tactics to each track and challenge. Focus on early economic investment, transition to Ring of Fire and MOAB Maulers by mid-game, and deploy Sun God or Dartling Gun combinations only when your finances allow. With practice and these expert strategies, you'll conquer Hard Mode, survive Apopalypse and Deflation modes, and experience the satisfaction of beating BTD4's ultimate MOAB challenges.
Sources: Ninja Kiwi official guides, Ayumilove strategy database, CrazyGames BTD4 analysis, Wizard101Central community guides
