GitHub - kimtg/NibblesSharp: QBasic Nibbles in C#

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!

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, 1-Player vs. AI, and 2-Player Gameplay:

  • Player 1 (SAMMY): Arrow keys (↑, ↓, ←, →)
  • Player 2 (JAKE): W, S, A, D (or autonomous AI in --vs-ai mode)
  • Responsive Input Buffering: 2-step input queue for razor-sharp cornering without dropped turns.
  • Persistent High Scores Leaderboard: Top-10 scores recorded and displayed (--scores).

• 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 & Vs-AI Mode (--demo / --vs-ai):

  • Built-in BFS pathfinding, cavity trap lookahead, and tail-following survival heuristics that navigate mazes smoothly.

• Comprehensive Unit Tests:

  • 35 automated unit tests verifying PLAY string parser, sound frequencies, arena boundaries, input buffering, high scores, coordinate conversions, level maps, and AI pathfinding.

Requirements

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

How to Run

Interactive Game (Standard)

Follow the classic QBasic prompts to select:

1. Game Mode: (1) Solo, (2) 1 Player vs Computer AI, (3) 2 Players
2. Starting Level (1 to 10)
3. Skill level (1 to 100, where 1=Novice, 90=Expert, 100=Twiddle Fingers)
4. Increase speed during play (Y or N)
5. Color or Monochrome monitor (C or M)

1-Player vs. Computer AI

Autonomous AI Demonstration Mode

Watch the computer play the game on its own:

View High Scores Leaderboard

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)
  --vs-ai           Play 1 Player against Computer AI (Jake)
  --quick           Skip intro and setup screens, start directly with defaults
  --players <1|2>   Set number of players (1 or 2)
  --level <1-10>    Set starting maze level (1 to 10)
  --skill <1-100>   Set game speed/skill level (1=Novice, 90=Expert, 100=Twiddle Fingers)
  --scores          Display high scores leaderboard
  --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

Game Controls

Running the Unit Tests

Executes 35 automated tests covering all core game logic, input buffering, high scores, sound systems, and AI heuristics.