Debugging: Inside the Machine

An AP Computer Science Review Game

Welcome to Inside the Machine, a browser-based platformer where you dive into a glitchy computer system, dodge rogue viruses, and debug your way to safety using real AP Computer Science concepts.

Play the Game!

About the Game

Inside the Machine turns AP CS review into an interactive adventure.
You play as a tiny avatar trapped inside a corrupted computer. System stability is dropping, viruses are everywhere, and the only way out is to:

  • Fix code glitches (by answering multiple-choice questions)
  • Recover the USB Key
  • Reach the USB Port before the system crashes

Along the way, you’ll revisit core AP Computer Science A (Java) or AP Computer Science Principles (pseudocode)topics in a way that feels more like a game than a worksheet.

Two Game Modes

Inside the Machine includes two distinct modes, each aligned to a different AP course:

1. APCS-A Mode (Java)

  • Uses real Java syntax and patterns that match the AP CS A Quick Reference
  • Focuses on:
    • Variables, conditionals, and loops
    • Arrays and ArrayLists
    • Methods and parameters
    • 2D arrays
    • Recursive methods and base cases
  • Ideal for students preparing specifically for the AP Computer Science A exam.

2. APCS-P Mode (Pseudocode)

  • Uses AP CSP-style pseudocode and list-based logic
  • Focuses on:
    • Selection and iteration in pseudocode
    • Lists, traversals, and list operations
    • Procedures with parameters and return values
    • Debugging logic in a language-neutral style
  • Perfect for AP Computer Science Principles students or for mixed classes where Java isn’t required.

Students (or teachers) can choose which mode to play depending on their course or review goals.

APCS-Principles vs. APCS-A

APCS-Principles
APCS-A

Gameplay

Goal:
Restore system stability, answer CS questions correctly, and escape through the USB Port.

Main Mechanics:

  • Move & Jump:
    • ←/→ or A/D to move
    • ↑ or Space to jump (hold to jump higher; some builds unlock double jump)
  • Interact with Glitches:
    • Get close to a glitch block and press C to open a CodeLens question
    • Press 1–4 to choose your fix
  • Stay Alive:
    • Viruses drain System Stability
    • Glitched tiles teleport you back if you try to stand on them before fixing them
    • Recover stability by grabbing the USB Key

Win Condition:

  1. Fix all the glitches in the level
  2. Retrieve the USB Key
  3. Reach the USB Port without leaving required glitches unfixed

Levels & Difficulties

Difficulty Levels

  • Easy
    • Fewer glitches and enemies
    • More generous platforms
    • Great for a first run or lighter review
  • Medium
    • More glitches and tighter jumps
    • Viruses are more threatening
    • Good for solidifying understanding
  • Hard
    • Dense glitches, tricky platforming
    • Precision movement required
    • Designed as a serious challenge and AP-style “boss level”

APCS-A & APCS-Principles Topics Covered

APCS-A (Java) Content

In APCS-A mode, CodeLens questions reinforce:

  • Variables, types, expressions, and casting
  • if, if-else, else-if chains
  • for loops, while loops, and nested iteration
  • Arrays and ArrayLists (traversal, off-by-one logic, indexing)
  • 2D arrays and row/column reasoning
  • Methods, parameters, return values, and tracing calls
  • Basic recursion (base cases, recursive step, call order)

APCS-P (Pseudocode) Content

In APCS-P mode, CodeLens questions emphasize:

  • AP CSP-style pseudocode
  • Sequences, selection, and iteration
  • Lists, indexing, APPEND, REMOVE, traversals
  • Procedures and parameters in pseudocode
  • Debugging logic in a language-independent way

What Makes It Different

  • Game First, Worksheet Second
    Students aren’t just clicking through questions; they’re navigating a live world, making jumps, avoiding viruses, and planning paths.
  • Integrated Review
    Every glitch is an opportunity to call on APCS-A Java or APCS-P pseudocode knowledge, depending on the chosen mode.
  • Choice of Course & Difficulty
    • Teachers can say, “Play APCS-A, Hard, Arrays & Loops”
    • Or “Play APCS-P, Medium, Lists & Selection”
  • Immersive Presentation
    Pixel-art motherboard backgrounds, floating virus sprites, and retro-inspired audio help it feel like an actual computer you’re cleaning from the inside.

For Teachers

Inside the Machine is designed for easy classroom adoption:

  • Browser-based – just share a URL, no installation
  • Flexible timing – quick 15–20 minute run or a full-class session
  • Supports both APCS-A and AP CSP in one game

Classroom Ideas

  • Pre-Test Review
    • APCS-A mode the day before a midterm or the AP test
    • APCS-P mode before big CSP assessments
  • Topic Targeting
    • Have students focus on arrays, ArrayLists, or recursion in APCS-A
    • Or lists, selection, and iteration in APCS-P
  • Reflection / Exit Ticket
    • Ask students to screenshot a missed question and explain:
      • Why their original answer was wrong
      • How to fix the code

Tips for New Players

  • Press C before you try to stand on a glitch tile.
    Fix it, don’t face-plant into it.
  • Remember: Jump is variable.
    Tap for short hops, hold for higher jumps.
  • Look for the USB Key before the USB Port.
    The port isn’t useful without the key.
  • If it feels too easy or too hard, change difficulty or switch modes (APCS-A vs APCS-P).

Ready to Go Inside the Machine?

Step into a corrupted system, dodge rogue viruses, and see how strong your APCS-A Java or APCS-P pseudocode skills really are.

Play the Game!