Introduction

In this project you’ll learn how to create a game, in which you have to match up coloured dots with the correct part of the controller.

Step 1: Creating a controller

Let’s start by creating a controller, that will be used to collect dots.

Activity Checklist

Start a new Scratch project, and delete the cat sprite so that your project is empty. You can find the online Scratch editor at jumpto.cc/scratch-new.
If your club leader has given you a ‘Resources’ folder, click ‘Upload sprite from file’ and add the ‘controller.svg’ image. You should move this sprite to the center of the stage.

If you don’t have this image, you can draw it yourself!
Turn your controller to the right when the right arrow key is pressed:
Test out your controller – it should spin to the right.

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Challenge: Spinning left

Can you make your controller spin to the left when the left arrow key is pressed?

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Step 2: Collecting dots

Let’s add some dots for the player to collect with their controller.

Activity Checklist

Create a new sprite called ‘red’. This sprite should be a small red dot.
Add this script to your ‘red’ dot sprite, to create a new dot clone every few seconds:
When each clone is created, you want it to appear in one of the 4 corners of the stage.

To do this, first create a new list variable called start positions and click the (+) to add in the values -180 and 180.
You can use these 2 list items to pick a random corner of the stage. Add this code to the ‘dot’ sprite, so that each new clone moves to a random corner and then slowly moves towards the controller.

The code above chooses either -180 or 180 for the x and y positions, meaning that each clone starts in one corner of the stage.
Test your project. You should see lots of red dots appear in each corner of the screen, and move slowly towards the controller.
Create 2 new variables called lives and score.
Add code to your stage to set the lives to 3 and the score to 0 at the start of the game.
You need to add code to the end of your red dot’s when I start as a clone code, so that either 1 is added to the player’s score if the colours match, or 1 is taken from the player’s lives if the colours don’t match.
Add this code to the end of your stage’s script, so that the game ends when the player loses all of their lives:
Test your game to make sure this code works as expected.

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Challenge: More dots

Duplicate your ‘red’ dot sprite twice, and name the two new sprites ‘yellow’ and ‘blue’.

screenshot

Edit these sprites (including their code), so that each coloured dot has to match the correct colour on the controller. Remember to test your project, making sure you gain points and lose lives at the right times, and that your game isn’t too easy or too hard!

screenshot

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Step 3: Increasing the difficulty

Let’s make the game get more difficult the longer the player survives, by slowly reducing the delay between dots appearing.

Activity Checklist

Create a new variable called delay.
On your stage, create a new script that sets the delay to a high number, and then slowly reduces the delay time.

Notice that this is very similar to how a game timer works!
Finally, you can use this delay variable in your red, yellow and blue dots’ scripts. Remove the code that waits a random number of seconds between creating clones, and replace it with your new delay variable:
Test your new delay variable, and see whether the delay between dots reduces slowly. Does this work for all 3 coloured dots? Can you see the value of the delay variable reducing?

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Challenge: Faster moving dots

Can you improve your game by adding a speed variable, so that the dots start off moving 1 step at a time, and steadily get faster and faster? This will work in a very similar way to the delay variable used above, and you can use this code to help you.

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Step 4: High score

Let’s save the high score, so that players can see how well they’re doing.

Activity Checklist

Create a new variable called high score.
Click on your stage, and create a new custom block called check high score.
Just before the end of the game, add in your new custom block.
Add code to your custom block to store the current score as the high score if it’s the highest score so far:
Test the code you’ve added. Play your game to check whether the high score is updated correctly.