BTD CE

Bloons Tower Defense for the TI-84 Plus CE calculator. Inspired by BTD5/BTD6 by Ninja Kiwi, rebuilt from scratch in C.

Features

Towers

8 fully upgradeable towers, each with 2 upgrade paths (4 levels per path):

Tower	Base Cost	Description
Dart Monkey	$200	Fast, cheap all-rounder with sharp darts
Tack Shooter	$280	Fires tacks in all directions
Sniper Monkey	$350	Infinite-range hitscan, hits one bloon instantly
Bomb Shooter	$525	Explosive splash damage
Boomerang Monkey	$325	Throws boomerangs with high pierce
Ninja Monkey	$500	Fast attack, detects camo, homing shurikens
Ice Monkey	$300	Area freeze, slows and damages nearby bloons
Glue Gunner	$250	Slows bloons, corrosive glue deals damage over time

Upgrade Abilities

• Splash damage (Bomb Shooter, Juggernaut)
• Homing projectiles (Seeking Shuriken, Missile Launcher)
• Damage over time (Corrosive Glue, Bloon Dissolver, Bloon Liquefier)
• Stun on hit (Bloon Impact, Flash Bomb)
• Aura slow (Arctic Wind)
• MOAB bonus damage (MOAB Mauler, Assassin, Eliminator)
• Permafrost, Distraction, Glue Soak, Camo stripping

Bloons

12 bloon types from Red to MOAB with full pop hierarchy:

Red > Blue > Green > Yellow > Pink > Black/White > Lead > Zebra > Rainbow > Ceramic > MOAB

• Camo bloons - invisible to most towers (Ninja detects by default, others need upgrades)
• Regrow bloons - regenerate to their original type over time
• Unique sprites for all camo, regrow, and camo+regrow variants
• Bloon immunities: Lead (sharp-immune), Black (explosion-immune), White (freeze-immune)

Game Modes

• 3 difficulties - Easy (40 rounds), Medium (60 rounds), Hard (80 rounds)
• Freeplay - endless scaling rounds after victory
• Sandbox - unlimited money for testing
• Spectate - watch the action after game over or victory
• 2x speed - fast-forward toggle

Targeting

4 targeting modes for each tower, cycled with the Mode key:

• First - targets the bloon furthest along the path
• Last - targets the bloon closest to the start
• Strong - targets the highest RBE bloon in range
• Close - targets the nearest bloon to the tower

Other Features

• Auto-save on round completion and menu exit
• Resume from save on launch
• Tower selling at 70% of invested value
• Difficulty-adjusted pricing (Easy 0.85x, Hard 1.08x, rounded to nearest $5)
• Hard mode income multiplier (0.8x)
• Spatial partitioning for efficient collision detection
• Deferred bloon spawn queue to prevent memory overflow from pop cascades

Controls

Key	Action
Arrow Keys	Move cursor
Enter	Place tower / Select tower / Confirm
+	Open tower buy menu
-	Sell tower (in upgrade screen)
2nd	Start round / Toggle 2x speed
Mode	Cycle target mode from game screen or upgrade menu
Del	Back / Cancel
Clear	Save and return to title screen

Installation

1. Connect your TI-84 Plus CE to your computer
2. Open TI Connect CE (or another transfer tool)
3. Transfer all 5 files to your calculator:
   • BTDCE.8xp
   • BTDTW1.8xv
   • BTDTW2.8xv
   • BTDBLN.8xv
   • BTDUI.8xv
4. Run BTDCE from the programs menu ([prgm] key)

OS 5.5.1+ users: You will need arTIfiCE to run assembly programs.

Building from Source

Prerequisites

• CE C SDK installed (set CEDEV environment variable)
• Python 3 with Pillow (pip install -r src/requirements.txt)

Build Steps

# Extract and process sprite images
cd src && python3 image_loader.py && cd -

# Generate sprite appvars
cd src/gfx && convimg && cd -

# Compile
make

Output files are in bin/.

Credits

• Original game by Ninja Kiwi
• Adapted for TI-84 Plus CE by Everyday Code, Elijah Baraw (2026)
• Art by Derek200 on DeviantArt

Eye Candy