Workshop › Space Invaders-style › Step 13 of 21

Bombs fall

What we are doing

Bombs fall 3 pixels a frame, slower than your bullets, and are dropped once they pass the bottom.

```js
const BOMB_SPEED = 3
  for (const bomb of bombs) bomb.y += BOMB_SPEED
  bombs = bombs.filter((bomb) => bomb.y < canvas.height)
```

What it means

• Same idea as the bullets, but downward: y grows.
• A bomb is kept while its top is still above the bottom of the canvas.

Your turn

1. Under BULLET_SPEED, write BOMB_SPEED.
2. In update, move the bombs under the bullet move line, and filter them under the bullet filter line.

Skills: Velocity and gravity

← They shoot back Lives →

All steps

1. The ship
2. The game loop
3. Move the ship
4. Stay on screen
5. Fire
6. Bullets fly
7. A short reload
8. The invaders
9. The march
10. Hit!
11. Score
12. They shoot back
13. Bombs fall
14. Lives
15. Game over
16. Best score
17. A wave in a function
18. Play again
19. Waves
20. Faster and faster
21. Build it yourself: an extra life