🧩 Grid Puzzle Challenge

A polished, grid-based mobile puzzle game built with Unity (C#) — featuring swipe-based controls, deterministic undo/redo history, and clean separation between game logic and UI rendering.

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📱 Demo & Download

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🎮 Core Features

• N × M Grid Simulation — logical grid model fully decoupled from the rendering layer
• Swipe-Based Input — gesture detection supporting Up, Down, Left, Right directions
• Undo / Move History — deterministic state stack; players can reverse any move
• HUD Display — live score, remaining moves, and win/lose overlay states
• Extra Gameplay Hook — power-ups and special tile mechanics for added depth

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🏗️ System Architecture Map

The app follows a strict 3-layer architecture ensuring separation of concerns:

┌─────────────────────────────────────────────────────────┐
│                        UI LAYER                         │
│          (Unity UI Toolkit / uGUI — rendering only)     │
│                                                         │
│  ┌─────────────┐  ┌────────────┐  ┌────────┐  ┌──────┐ │
│  │  GameScreen │→ │  GridView  │  │ HUDBar │  │Overlay│ │
│  │ Root canvas │  │Tile render │  │Score/  │  │Win/  │ │
│  └─────────────┘  └────────────┘  │Moves   │  │Lose  │ │
│                                   └────────┘  └──────┘ │
└──────────────────────┬──────────────────────────────────┘
                       │  State events (no direct UI calls)
┌──────────────────────▼──────────────────────────────────┐
│                   GAME LOGIC LAYER                      │
│        (Pure C# — no UnityEngine.UI dependencies)       │
│                                                         │
│  ┌─────────────────┐  ┌────────────┐  ┌─────────────┐  │
│  │ InputController │→ │ GameEngine │→ │ GridManager │  │
│  │ Swipe→Direction │  │Orchestrator│  │N×M operations│ │
│  └─────────────────┘  └─────┬──────┘  └─────────────┘  │
│                             │                           │
│                    ┌────────▼────────┐                  │
│                    │ HistoryManager  │                  │
│                    │   Undo stack    │                  │
│                    └─────────────────┘                  │
└──────────────────────┬──────────────────────────────────┘
                       │  Read immutable models
┌──────────────────────▼──────────────────────────────────┐
│                     DATA LAYER                          │
│            (Immutable C# models — no side effects)      │
│                                                         │
│   GridState   │   TileModel   │  MoveRecord  │GameConfig│
└─────────────────────────────────────────────────────────┘

Layer Responsibilities

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🔄 Functional Code Flow

Complete data pipeline from user input to UI update:

User Gesture (Swipe)
        │
        ▼  Input.touch / pointer events
┌───────────────────┐
│  InputController  │  ← Validates gesture, emits Direction enum
└────────┬──────────┘
         │  Direction event
         ▼
┌───────────────────┐         ┌─────────────────┐
│    GameEngine     │────────▶│  HistoryManager │
│   Orchestrator    │  push   │  Undo stack     │
└────────┬──────────┘         └─────────────────┘
         │  move(direction)
         ▼
┌───────────────────┐
│   GridManager     │  ← Computes new GridState (pure function)
│  N×M operations   │
└────────┬──────────┘
         │  emit GridState
         ▼
┌───────────────────┐
│   EventBus /      │  ← Broadcasts immutable state to all listeners
│   ScriptableObj   │
└────────┬──────────┘
         │  OnStateChanged()
         ▼
┌───────────────────┐
│  UI Rendering     │  ← GridView, HUDBar, Overlay re-render
│  (Unity uGUI)     │
└───────────────────┘

        ↑
        │  Undo: pop stack → restore previous GridState
        └──────── HistoryManager ──────────

Flow Description

1. User Gesture — Player swipes on screen; Unity's touch/pointer system captures the raw input.
2. InputController — Translates gesture into a typed Direction enum; filters invalid inputs.
3. GameEngine — Central orchestrator; dispatches the move to GridManager and records it in HistoryManager.
4. GridManager — Executes the grid transition algorithm, returning a new immutable GridState.
5. EventBus / ScriptableObject — Receives the new state and broadcasts it to all subscribed UI listeners.
6. UI Rendering — Unity uGUI components rebuild reactively; GridView, HUDBar, and Overlay update independently.

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📂 Project Structure

Assets/
├── Scripts/
│   ├── Data/
│   │   ├── GridState.cs          # Immutable board state
│   │   ├── TileModel.cs          # Single tile data
│   │   ├── MoveRecord.cs         # Undo history entry
│   │   └── GameConfig.cs         # Grid size, rules config
│   ├── Logic/
│   │   ├── InputController.cs    # Gesture → Direction
│   │   ├── GameEngine.cs         # Orchestration layer
│   │   ├── GridManager.cs        # N×M grid algorithms
│   │   └── HistoryManager.cs     # Undo/redo stack
│   ├── UI/
│   │   ├── GameScreen.cs         # Root canvas controller
│   │   ├── GridView.cs           # Tile grid renderer
│   │   ├── HUDBar.cs             # Score / moves display
│   │   └── OverlayManager.cs     # Win / lose overlays
│   └── Core/
│       └── EventBus.cs           # Decoupled state broadcaster
├── Prefabs/
├── Scenes/
└── Resources/

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⚙️ Tech Stack

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🚀 Getting Started

# Clone the repository
git clone https://github.com/rohit892004/Capsitech_Task.git

# Open in Unity Hub
# Select Unity 2022 LTS or compatible version

# Build APK
# File → Build Settings → Android → Build

Or download the prebuilt APK directly from the Google Drive link.

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📝 Commit Convention

This project follows semantic commit prefixes:

feat:     New feature
fix:      Bug fix
refactor: Code restructure (no behaviour change)
docs:     Documentation update
test:     Test additions or changes
chore:    Build / config changes

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📄 License

This project was developed as part of a technical assessment for Capsitech IT Services.