CREATE YOUR FIRST GAME
In the first project, Dancing Cat, you discovered
how to control a Sprite by stacking blocks in a
certain sequence.
In this project you will build on those skills.
Use Control, Sensing, and Looks blocks to make
the mouse appear to be eaten when touched by
the cat.
Start Scratch
10/18/14 Download Instructions
Need Help?
NEW CONCEPTS
LEARN HOW TO:
NEW BLOCKS INTRODUCED:
ADD NEW SPRITES TO
THE GAME STAGE
GIVE SPRITES
MOVEMENT
CONTROL SPRITE ACTION
DURING A GAME
The Forever block gives a sprite continuous instruction.
Whatever is contained in the Forever block is run all the time.
With the If … Then block the sprite makes a decision based on a
condition you, the game builder, set when you create the game.
The block tells the Sprite to perform an action if the condition is
true.
The light blue Sensing blocks set the condition where a change
is made to the sprite’s movement.
10/18/14 ADD CAT GAME SPRITE
TOOLS YOU WILL NEED
You need a Cat and a Mouse for this game. You can change or
add sprites using the Sprite Library.
First, delete the default cat sprite. We are going to use a
different cat sprite for this game. Right click on the sprite and
select delete from the list that appears.
Now click the Choose Sprite from Library button. Select the
Animals category. The Cat2 sprite looks like a cat that would
chase a mouse! Double-click on Cat2. Notice that your new
sprite is automatically added to the stage.
10/18/14 ADD CAT CONTROLS
BLOCKS YOU WILL NEED
Now it is time to build the code for the cat. In this game you want
to make the cat move and bounce if it touches a wall. The cat
should do these two things forever.
To start we will give you the exact instructions :
Click the Events block option. Drag the When
block over into the script area.
Clicked
Next, drag the Forever block to the script area and snap it below
the When Clicked block.
Drag a Move … Steps block to the script area and snap it inside
the Forever block. Leave the number of steps at 10.
Finally, drag the If On Edge, Bounce block and snap underneath
the Move <> Steps block. This tells the sprite to turn and run in
another direction when it touches the edge of the stage. After
all, we don’t want the cat running off the stage out of the game!
Click on the green Show Me button to see the solution
10/18/14 Show Me
ADD MORE CAT CONTROLS
BLOCKS YOU WILL NEED
Now you need to take control of the cat. Add blocks that make the cat
turns left or right if when it senses that the left and right arrow keys
have been pressed.
Drag your blocks to the stage. You need two If … Then blocks and two
of the Key … Pressed? Blocks for a total of 6 blocks.
On the Key … Pressed? Blocks. Click the small
black down arrow and select Right Arrow in one of
the blocks and Left Arrow in the other block.
Drop them in between the If and Then in each of the If … Then blocks.
Add the Turn (left) … Degrees block inside the If … Then block with the
Left Arrow sensing block. Do the same for the Turn (right) … Degrees
block
10/18/14 Show Me
COMPLETE AND TEST CAT CONTROLS
BLOCKS YOU WILL NEED
Final Assembly is easy. Drop the If … Then block sets inside the
forever block so you evaluate the if condition all the time.
Here is what your finished block of code should look like to give the
cat movement during the game.
Try it!
Click the green flag above the
stage to start the cat moving. Use
the left and right arrow keys to
turn the cat left and right.
10/18/14 ADD MOUSE GAME SPRITE
TOOLS YOU WILL NEED
Now add a mouse sprite to the game. Use the Sprite Library just
as you did for adding the cat sprite.
Click the Choose Sprite from Library button. Select the Animals
category. Double-click on Mouse1. Notice that your new sprite
is automatically added to the stage.
10/18/14 ADD MOUSE CONTROLS
BLOCKS YOU WILL NEED
Now it is time to program the mouse movement. Before you start
dragging blocks, make sure the Mouse sprite is selected!
For this step we just want the mouse to move on its own, forever.
At this point, you should be able to do this on your own. To get
help or check your work click on the Show Me button.
Here are a few hints:
Don’t forget to start the script with a When Clicked block.
Make sure the Move is inside the Forever Block.
Click on the Show Me button to check your work.
Show Me
10/18/14 ADD MORE MOUSE CONTROLS
Let’s building the smarts into the mouse sprite.
BLOCKS YOU WILL NEED
Here we want the Mouse to sense 3 conditions and do something.
1.  If the mouse touches the edge turn 40 Degrees so he does not
run off the stage.
2.  If the cat touches the mouse hide the mouse so it looks like the
cat ate the mouse.
3.  If the space key is pressed restart the game. To restart the
game simply show the mouse again.
Here are some hints:
Show Me
10/18/14 COMPLETE MOUSE CONTROLS
BLOCKS YOU WILL NEED
Final Assembly is easy. Drop the If … Then block sets inside the
forever block so you evaluate the if condition all the time.
Here is what your finished block of code should look like to give the
mouse movement during the game.
Try it!
Click the green flag above the
stage to start the cat moving. Use
the left and right arrow keys to
turn the cat left and right.
10/18/14 PLAY THE GAME
Try it!
Click the green flag above the stage to
start the cat and mouse moving.
Use the left and right arrow keys to turn the
cat toward the mouse.
If the cat eats the mouse, use the space
bar to bring the mouse back to life.
10/18/14 10/18/14