Build and Debug the Core Features

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1 What We're Building
2 Introduction
3 Open Your Saved Arcade Project
4 Create Your Sprite
5 Move Left and Right
6 Add Gravity
7 Draw the Map
8 Jump
9 Move Through the Map
10 Only Jump When Touching Ground
11 Danger Tiles
12 Goal
13 Game Time
14 Code Talk — What Worked and What We'd Change
15 What You Covered
Pupil practice

1 - What We're Building ~5 mins

Illustration for What we're building Programmers rarely get a game working perfectly the first time — a huge part of the job is testing, spotting when something goes wrong, and fixing it. That's called debugging, and today you'll do exactly what game developers do all day.

You'll reopen the platform game you saved last time and keep building it. Watch the board as each new piece is modelled, then add it on your own device and run it to see what happens. When something behaves unexpectedly, that's not a mistake — it's your next puzzle to solve.

Teacher Notes

Open by reminding pupils this is the next part of their ongoing project. Make sure every pair reopens the project they saved previously before anything else. Ask: 'What did we get working last time?' Model the first piece on the IWB before pupils touch their devices. Support cue: pair a confident pupil with one who needs help finding the saved file.

👇 Mark your steps as done as you complete them.

+5 XP

2 - Introduction ~2 mins

Platform games (often simplified as platformer or jump 'n' run games) are a video game genre of action games in which the goal is to move the player character between points in an environment. Platformers use in jumping and climbing to navigate the player's environment and reach their goal. Levels and environments feature uneven terrain and suspended platforms of varying height that requires use of the player character's abilities in order to traverse them.

Teacher Notes

Read this framing aloud to set the scene for the platform game genre. Ask pupils to name platform games they know so the goal — get the character from start to goal across platforms — feels concrete. No device work needed here; keep it brief.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Open Your Saved Arcade Project ~2 mins

Go to the arcade.makecode.com website and open the project you saved last time. Do not start a new one — today you are adding to the game you already built.

Arcade: How to create a new project

Create a new Arcade project using the makecode.com website.

Teacher Notes

Show on the IWB how to reach the site and reopen the saved project. Key question: 'Is everyone on arcade.makecode.com and not a different page?' Watch for pupils starting a brand-new project when they should be continuing the saved one — check they are in the right place.

+10 XP

4 - Create Your Sprite ~4 mins

In this game you will control a sprite and move it from the start of the map, to the goal at the end.

Add the following code to your project to create your sprite and use the sprite editor to design your character.

let mySprite = sprites.create(img`
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    5 5 f f f f f f f f f f 5 5 5 5 
    5 5 5 f f f f f f f f 5 5 5 5 5 
    5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 
    `, SpriteKind.Player)

Arcade: How to create a sprite in Arcade

Click on the gray box in the sprite block to open the Editor. You can choose a sprite from the Gallery or you can paint your own sprite using the Editor.

Teacher Notes

Model creating the sprite and opening the sprite editor on the IWB. Encourage pupils to design their own character but not to spend the whole lesson decorating. Common issue: pupils lose the sprite editor — show how to reopen it. Extension: let fast finishers refine their sprite art later.

+10 XP

5 - Move Left and Right ~5 mins

In the game we will use the left and right buttons to move our sprite.

Add the following new code:

let mySprite = sprites.create(img`
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    5 5 5 f f 5 5 5 5 f f 5 5 5 5 5 
    5 5 5 f f 5 5 5 5 f f 5 5 5 5 5 
    5 5 5 f f 5 5 5 5 f f 5 5 5 5 5 
    5 5 5 f f f f 5 5 f f f f 5 5 5 
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    5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 
    5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 
    5 f 5 5 5 5 5 5 5 5 5 5 5 f 5 5 
    5 f f 5 5 5 5 5 5 5 5 5 f f 5 5 
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    5 5 f f f f f f f f f f 5 5 5 5 
    5 5 5 f f f f f f f f 5 5 5 5 5 
    5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 
    `, SpriteKind.Player)
controller.moveSprite(mySprite, 100, 0)

Click the + to set the vx value to 100 and the vy value to 0. We set the vy value to 0 so that up and down buttons do not move the sprite.

Test that you can move your character left and right but not up and down.

Teacher Notes

Model adding the left/right movement, then have pairs run it immediately to see the sprite move. Key question: 'Does your sprite respond to both buttons?' If it only moves one way, check both button pieces were added. Safety-free step — keep the run-test habit going.

+10 XP

Pupil practice · Investigation Journal

Module 4 · Technology: a Coding Build, Micro:bit Data and Presenting Data

Lesson 24 · Build and Debug the Core Features

Download Investigation Journal sheet (PDF)

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This lesson is copyright of Coding Ireland 2017 - 2025. Unauthorised use, copying or distribution is not allowed.

Teacher Class Feed

1 - What We're Building ~5 mins

2 - Introduction ~2 mins

3 - Open Your Saved Arcade Project ~2 mins

4 - Create Your Sprite ~4 mins

5 - Move Left and Right ~5 mins

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XP