QBasic Nibbles in C# (.NET 10)

An authentic, faithful modern recreation of the classic 1990 MS-DOS Microsoft QBasic game Nibbles (NIBBLES.BAS by Rick Raddatz) written in C#.

Runs directly in your terminal with zero flickering, authentic PC-Speaker sound effects, subpixel text rendering, and all 9 original levels!

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Features

• Authentic QBasic Visuals & Text Mode Simulation:

  • Uses the original CP437/Unicode half-block rendering method (▀, ▄, █) to achieve 80x50 virtual resolution in standard 80x25 terminal text mode.
  • Classic QBasic color scheme: Navy Blue playing arena, Yellow Sammy, Light Magenta Jake, Light Red walls, and Bright White/Red dialogs.
  • Supports both Color and Monochrome monitor modes.
  • Title screen with the animated flashing sparkle border.
  • Classic 10-pass interlaced dissolving death animation when a snake crashes.

• Authentic IBM PC Speaker Sound Engine:

  • Built-in interpreter for the original QBasic PLAY macro strings.
  • Synthesizes 8-bit square wave audio matching the vintage Intel 8253 PIT PC Speaker buzzer.
  • Plays non-blockingly via Windows winmm.dll (with Console.Beep fallback).
  • Contains all 4 iconic musical cues and sound effects:
    1. Intro Theme: MBT160O1L8CDEDCDL4ECC
    2. Round Start: T160O1>L20CDEDCDL10ECC
    3. Eat Number: MBO0L16>CCCE
    4. Death Crash: MBO0L32EFGEFDC
  • Press M anytime to toggle mute.

• 1-Player and 2-Player (Simultaneous) Gameplay:

  • Player 1 (SAMMY): Arrow keys (↑, ↓, ←, →)
  • Player 2 (JAKE): W, S, A, D

• All 9 Classic Level Mazes + Endless Mode:

  • Every wall coordinate, player spawn point, and initial direction is mathematically identical to the original Microsoft source code.
  • Level 1: Open arena
  • Level 2: Horizontal center barrier
  • Level 3: Dual vertical pillars
  • Level 4: Opposing corner barriers
  • Level 5: Enclosed central box with corner gaps
  • Level 6: 7 vertical bars with central corridor
  • Level 7: Dotted vertical dividing line
  • Level 8: Interleaved vertical comb
  • Level 9: Diagonal barriers
  • Level 10+: Staggered obstacle field

• Autonomous AI Demo Mode (--demo):

  • Built-in BFS pathfinding and flood-fill survival AI that plays the game autonomously so you can watch and verify gameplay without touching the keyboard.

• Comprehensive Unit Tests:

  • 18 automated unit tests verifying PLAY string parser, sound frequencies, arena boundaries, coordinate conversions, level maps, and AI pathfinding.

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Requirements

• .NET 10 SDK (or .NET 8 / 9)
• Any terminal supporting UTF-8 (Windows Terminal, PowerShell, CMD, VS Code Terminal, etc.)

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How to Run

Interactive Game (Standard)

dotnet run

Follow the classic QBasic prompts to select:

1. Number of players (1 or 2)
2. Skill level (1 to 100, where 1=Novice, 90=Expert, 100=Twiddle Fingers)
3. Increase speed during play (Y or N)
4. Color or Monochrome monitor (C or M)

Autonomous AI Demonstration Mode

Watch the computer play the game on its own:

dotnet run -- --demo

Quick Start (Skip intro prompts)

dotnet run -- --quick --players 1 --skill 50

Command-Line Options

Usage:
  dotnet run [options]

Options:
  --demo            Run autonomous AI demonstration mode (press Esc or key to exit)
  --quick           Skip intro and setup screens, start directly with defaults
  --players <1|2>   Set number of players (1 or 2)
  --skill <1-100>   Set game speed/skill level (1=Novice, 90=Expert, 100=Twiddle Fingers)
  --color           Enable color mode (Default: Blue background, Yellow/Magenta snakes)
  --mono            Enable monochrome monitor mode
  --mute            Start with sound muted
  --no-accel        Disable game speed acceleration across levels
  -h, --help        Show this help message

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Game Controls

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Running the Unit Tests

dotnet test

Executes 18 automated tests covering all core game logic and sound systems.