Build and Debug the Core Features

Warning: Your screen size is quite small for viewing this. Rotate your device into landscape mode if you can.

1 What We're Building
2 Introduction
3 Create a New 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 Today you're a game programmer. The people who make the games you play don't write everything perfectly the first time — they build a small piece, run it, and watch what happens. When something goes wrong, that's called a bug, and finding and fixing it is a huge part of the job.

Key point

We're going to build a platform game where you guide a character across ledges to reach a goal — while dodging danger. Watch the board as we model each piece, then build it on your own device and press play to see what it does. Keep your Investigation Journal handy, because you'll be catching at least one bug today.

👇 Mark your steps as done as you complete them.

+5 XP

2 - Introduction ~2 mins

A platform game is a game where you guide a character across ledges and platforms to reach somewhere. Mario, Sonic and Hollow Knight all work this way. The ground is never flat: there are gaps to clear, ledges at different heights and platforms hanging in mid-air, so the only way forward is to run and jump.

That means your character needs a small set of abilities — moving left and right, jumping, and something to avoid — and the level is built to test them. Everything you are about to code today is one of those abilities.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Create a New Arcade Project ~2 mins

Go to the arcade.makecode.com website and create a new project.

Arcade: How to create a new project

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

+10 XP

4 - Create Your Sprite ~5 mins

A sprite is a character or object in the game that the code can move around. In this game you will control one sprite and move it from the start of the map to the goal at the end.

Key point

Add the following code to your project to create your sprite. Clicking the little picture inside the block opens the sprite editor, a grid where you colour in your character square by square.

let mySprite = sprites.create(img`
    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 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 
    5 5 5 f f f f 5 5 f f f f 5 5 5 
    5 5 5 f f f f 5 5 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 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 
    5 5 f f f f f f f f f f f 5 5 5 
    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.

+10 XP

5 - Move Left and Right ~6 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`
    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 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 
    5 5 5 f f f f 5 5 f f f f 5 5 5 
    5 5 5 f f f f 5 5 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 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 
    5 5 f f f f f f f f f f f 5 5 5 
    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 + on the block to show two speed settings. vx is the speed left and right, and vy is the speed up and down. Set vx to 100 and vy to 0. With vy at 0 there is no up-and-down speed at all, so the up and down buttons will not move the sprite.

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

+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)

123learn · Online learning platform

Unlock the full learning experience

You're previewing this lesson. Get full access to this lesson and hundreds more — each one ready to teach, with interactive activities, printable resources and pupil progress tracking built in.

Hundreds of curriculum-aligned lessons

Interactive activities in every lesson

Printable resources & progress tracking

Get started

Copyright Notice
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 - Create a New Arcade Project ~2 mins

4 - Create Your Sprite ~5 mins

5 - Move Left and Right ~6 mins

Unlock the full learning experience

XP