IMMUTABLE TOWERS  

A functional interpretation of the classic Tower Defense genre, implemented in Haskell with a graphical interface powered by gloss. Players must strategically position towers to prevent waves of enemies from reaching their base, utilizing different projectile types with unique synergies and effects. Built for Laboratórios de Informática I (1st year, Software Engineering — Universidade do Minho).

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Hall of Fame

This project was featured in the LI1 Hall of Fame at Universidade do Minho.

Play the game online: Immutable Towers - Web Version

Browse other featured projects: LI1 Hall of Fame

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Requirements

Dependency	Notes
GHC	Glasgow Haskell Compiler
Cabal	Haskell build tool
gloss	Graphics library for rendering
HUnit	Unit testing framework

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Build

From the project root:

cabal build

This produces the game executable from the Haskell sources.

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Usage

Play the game

Launch the interactive graphical interface:

cabal run

The game features:

• Mouse-driven interaction for tower placement and upgrades
• Strategic resource management through the in-game shop
• Progressive difficulty through wave-based enemy spawning
• Level progression system with save/load functionality

Run tests

Execute the automated test suite:

cabal test

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Gameplay Mechanics

Terrain Types

• Grass — standard buildable terrain
• Dirt — alternative buildable surface
• Water — non-buildable obstacle

Tower Types & Projectiles

Projectile	Effect
Fire	Continuous damage over time
Ice	Freezes enemies, halting movement
Resin	Reduces enemy movement speed
Poison	Applies weaker Fire and Resin effects simultaneously
Laser	High-damage precision targeting

Enemy System

• Dynamic enemy states with directional movement
• Health and speed attributes
• Portal-based wave spawning system
• Visual status indicators and animations

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Repository Layout

immutable-towers/
├── src/
│   ├── Main.hs              # Gloss-based graphical interface
│   ├── Jogo.hs              # Global game state management
│   ├── Mapa.hs              # Map representation and validation
│   ├── Base.hs              # Player base state and mechanics
│   ├── Torre.hs             # Tower definitions and projectile logic
│   ├── Inimigo.hs           # Enemy movement and effect system
│   ├── Portal.hs            # Wave generation and portal management
│   └── Testes.hs            # HUnit test suite
├── images/                  # Game sprites and visual assets
│   ├── inimigo/             # Enemy directional sprites
│   ├── torre/               # Tower graphics
│   └── terreno/             # Terrain tiles
├── Enunciado.pdf            # Original project specification (Portuguese)
└── *.cabal                  # Cabal project configuration

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Extended Features

This implementation includes several enhancements beyond the base requirements:

• Isometric rendering — Rich visual representation with depth perception
• Advanced tower mechanics — Including laser-based towers with unique targeting
• Mouse interaction — Click-based tower purchasing and positioning
• Visual effects — Animations for combat, projectiles, and game events
• Level progression — Multi-stage difficulty scaling
• Persistent state — Save and load game functionality

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Testing

The project includes comprehensive unit tests implemented with HUnit.

Run the full test suite:

cabal test

Test coverage includes:

• Map validation logic
• Enemy pathfinding and state transitions
• Tower targeting and damage calculations
• Projectile synergy effects
• Portal wave generation

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Documentation

For detailed project specification and requirements, refer to:

• Enunciado.pdf — Original project statement (Portuguese)

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Authors

• Guilherme Ferreira - A111042
• Lucas Pinto - A111042