Snake is a classic game where the player will control a small snake using arrow key controls. When the snake eats a collectable item on the map, it'll grow in length.
Fun, right? Let's take a look at how to easily create Snake (and easy games like it) in Scratch.
Sprite Creation
For a Snake game, there are two Scratch sprites that need to be created. One is the snake sprite and the other is the item the snake will be chasing. In this case, that collectable item will be an apple. Scratch Paint can be used to make the sprites.
Design a Snake
The snake will actually be divided into two sprites: its head and body. The body will follow the head sprite around the map and grow as the snake collects items.
1. Go to Scratch > Create to start a new project titled "Snake Game".
2. Hover over the Choose a Sprite button and select Paint.
3. Draw a circle for the snake's head, using a black outline on the shape.
4. Draw a pink tongue for the snake, and click Back to place it under the snake's head.
Draw the Body
The snake's body will be drawn separately, so it can grow as the snake collects more items without affecting the snake's head.
1. Hover over the Choose a Sprite button and select Paint to create a new sprite.
2. Draw a circle with no outlines for the snake's body.
Line Up the Snake
Now, with two parts of the snake - the head and the body - you can line them up in the game preview window (you might need to resize them).
1. Adjust the snake sprites so that they're small and centered on the screen.
2. Move the body slightly to the left of the head, so they look connected.
Here is a Scratch coding tip: he snake's body should be about 1/3rd the size of its head. It should also slightly overlap the head, so it looks like a neck.
The sprites should be small on the screen so the player has plenty of space to move around and collect items.
Snake Movement
Just to be clear, in this game, the snake will constantly be moving forward. It's up to the player to then control the snake's direction using arrow key commands.
Movement
To create movement:
1. Select the Snake Head sprite and add when flag clicked to the code area.
2. Attach point in direction 90 and go to x, y 0, 0 to the block.
3. Attach a forever ↺ block with move 5 steps inside.
Control
To control the snake:
1. Add when space key pressed and set it to up arrow.
2. Attach point in direction 0 to the block.
3. Right-click and duplicate the block, and set it to down arrow with a direction of 180.
4. Duplicate the block two more times.
5. Set one to right arrow with a direction of 90, and left arrow at -90.
As can be seen in the image above, the snake's body doesn't follow the head. This is because there isn't any code attached to it yet, so the body doesn't know what to do.
To make the body look connected, it will need to be coded to follow the head sprite.
Follow the Leader
Select the Snake Body sprite and add when flag clicked to the code area.
Attach point in direction 90 and a go to x, y block.
Attach a forever ↺ block with point towards and move 5 steps inside.
Choose Snake Head from the dropdown for the point towards block.
Changing Length
As a reminder, for the snake to grow, it needs to collect items (like the apple). In this game, any time the snake eats an apple, its tail will grow in length.
To track the snake's length, a variable needs to be created. This variable will track how many apples the snake eats, which will then be equal to how long the snake is.
Variables
This game will use two variables: a score and a length variable, which will determine how long the snake becomes.
In the Code tab, select Variables and click Make a Variable.
Create a variable named score and a variable named length.
Set the Length
The snake's body will grow every time it eats an apple. To do this, it'll create clones of itself equal to the amount it's eaten.
1. Select the Snake Body sprite.
2. Attach the set length to 0 block to the top of its code.
3. Drag a create clone of myself block into the forever ↺ block (at the bottom).
4. Add when I start as a clone to the code area.
5. Attach wait and delete this clone to the block.
6. Drag the length variable into the wait block.
The length is set, but currently, the length will always be 0, because the variable isn't being changed. To change the variable, create and code the collectable item.
Collecting Items
For the snake to grow, you'll need to design an item sprite that the snake can eat.
Create a Collectable
This example uses an apple, but you can design any collectable item you want!
1. Hover over the Choose a Sprite button and select Paint to create a new sprite.
2. Draw a collectable item.
Set the Position
The apple will appear at random points on the map, making it impossible to predict where it'll show up next!
1. Select the Apple sprite and attach when flag clicked to the code area.
2. Attach a set score to 0 block. Eating apples will earn points for the player.
3. Attach go to random position, if on edge, bounce, and point in direction 90 to the code.
Collecting Apples
When the snake touches an apple, both the score and length variables will increase. The apple will also disappear, and then reappear in a new location.
1. Add when flag clicked with a forever ↺ block to the code area.
2. Attach an if then <> block with <touching Snake Head?> in the bracket.
3. Inside the if statement, add hide with change length by 0.1 and change score by 10.
4. Add a broadcast block in the statement with the message "Reset Apple".
Reset the Apple
1. Add when I receive Reset Apple to the code area.
2. Duplicate the go to random position code blocks onto the receive block.3
3. Attach a show block to the code.
And that's it! you should now have a Snake game to play in scratch. Thinking about what the next steps could be? Kids can consider things like adding a "game over" if the snake touches its own body or the map border.
If they are stuck and need help, consider our many online coding classes for kids or Scratch summer camps.