2D breakout game pure JS tutorial problems

### MDN URL

https://developer.mozilla.org/en-US/docs/Games/Tutorials/2D_Breakout_game_pure_JavaScript/Finishing_up

### What specific section or headline is this issue about?

See comments

### What information was incorrect, unhelpful, or incomplete?

1. In **Paddle and keyboard controls** is the statement

You can find the source code as it should look after completing this lesson at Gamedev-Canvas-workshop/lesson4.html.

This is not true. There is no _Start game_ button, which, if included as discussed in **Bounce off the walls** (including _runButton.disabled = true;_), will cause the event handlers _keyDownHandler_ and _keyUpHandler_ not to be registered and the paddle not to respond to arrow movements.

2. In **Collision detection** is the statement

Update the following part of the code as indicated by the highlighted line:

There is no highlighted line. This statement also appeared in other places in the tutorial.

3. In **Collision detection** in **Compare your code** the Play button activates a game in which the paddle does not move.

4. In **Track the score and win**, there is a highlighted line.

5. In **Track the score and win**, I think _drawScore()_ should be placed under _collisionDetection()_.

Environment:

Windows 7 Professional SP 1
Notepad++ v8.7.9 (64 bit)
Firefox 115.29.0ers (64 bit)

### What did you expect to see?

See above

### Do you have any supporting links, references, or citations?

_No response_

### Do you have anything more you want to share?

Tutorial was lots of fun and very instructive. Kudos!!!

### MDN metadata

Page report details

* Folder: `en-us/games/tutorials/2d_breakout_game_pure_javascript/finishing_up`
* MDN URL: https://developer.mozilla.org/en-US/docs/Games/Tutorials/2D_Breakout_game_pure_JavaScript/Finishing_up
* GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/games/tutorials/2d_breakout_game_pure_javascript/finishing_up/index.md
* Last commit: https://github.com/mdn/content/commit/6036cd414b2214f85901158bdf3e3a96123d4553
* Document last modified: 2025-09-18T15:38:35.000Z