Code a Platformer Game | 1. The Basics

3 min read 1 month ago
Published on Jun 20, 2025 This response is partially generated with the help of AI. It may contain inaccuracies.

Introduction

In this tutorial, you will learn how to create a basic platformer game in Scratch, following the steps outlined in the first episode of griffpatch's series. This guide will help you set up your game with essential mechanics like gravity, collisions, and jumping, making it suitable for both beginners and more advanced users.

Step 1: Set Up Your Backdrop

  • Open your Scratch project and select the backdrop.
  • Choose a simple backdrop that fits a typical platformer theme, like a landscape or level design.
  • Use the Scratch costume editor to customize your backdrop if desired.

Step 2: Implement Gravity

  • Create a new sprite for your player character, named "Guy."
  • In the code area, add a script to simulate gravity
    • Use the when green flag clicked block.
    • Set a variable for gravity (e.g., gravity = -1).
    • Continuously change the Y position of the player by the gravity value.
when green flag clicked
forever
    change y by gravity
end

Step 3: Manage Ground Collisions

  • Define the ground level in your game.
  • Use collision detection to prevent the player from falling through the ground.
  • Add a conditional check to see if the player is touching the ground sprite and reset the Y position accordingly.
if <touching [ground v]> then
    set y to [ground level]
end

Step 4: Enable Jumping

  • Create a jumping mechanic by using keyboard input.
  • Add a when [space v] key pressed block to initiate a jump.
  • Change the Y position upward to create a jumping effect.
when [space v] key pressed
if <touching [ground v]> then
    change y by 10  // Adjust value for jump height
end

Step 5: Implement Walking

  • Allow the player to move left and right using the arrow keys.
  • Add the following scripts to control movement:
when [right arrow v] key pressed
    change x by 5

when [left arrow v] key pressed
    change x by -5

Step 6: Address Horizontal Collisions

  • Ensure that the player cannot walk through walls or obstacles.
  • Add collision detection to stop horizontal movement when touching a wall sprite.
if <touching [wall v]> then
    change x by -5 // Reverse movement if colliding
end

Step 7: Fix Jumping Mechanics

  • Make adjustments to ensure smoother jumping and prevent glitches.
  • Check if the player is allowed to jump only when touching the ground to avoid double jumps.

Step 8: Troubleshoot Stuck to Ceiling Bug

  • Identify and fix issues where the player might get stuck on the ceiling.
  • Add conditions to check for upward movement and adjust Y position if necessary.

Step 9: Experiment with Physics

  • Tweak gravity, jump height, and movement speed to refine game mechanics.
  • Playtest your game frequently to identify any adjustments that enhance the player experience.

Conclusion

Congratulations! You have successfully set up the fundamentals of a platformer game in Scratch. You’ve learned how to implement gravity, collisions, jumping, and walking mechanics. For further enhancement, consider exploring features like animations, moving platforms, and more complex level designs. Check out the next episode for advanced techniques!