Choosing animations

Now that the player can move, you need to change which animation the AnimatedSprite is playing based on whether it is moving or standing still. The art for the run animation faces to the right, which means it should be flipped horizontally (using the Flip H property) for movement to the left. Add this to the end of your _process() function:

    if velocity.length() > 0:
        $AnimatedSprite.animation = "run"
        $AnimatedSprite.flip_h = velocity.x < 0
    else:
        $AnimatedSprite.animation = "idle"

Note that this code takes a little shortcut. flip_h is a Boolean property, which means it can be true or false. A Boolean value is also the result of a comparison like <. Because of this, we can set the property equal to the result of the comparison. This one line is equivalent to writing it out like this:

if velocity.x < 0:
    $AnimatedSprite.flip_h = true
else:
    $AnimatedSprite.flip_h = false     

Play the scene again and check that the animations are correct in each case. Make sure Playing is set to On in the AnimatedSprite so that the animations will play.